High Density O-Glycosylation on Tandem Repeat Peptide from Secretory MUC1 of T47D Breast Cancer Cells

The site-specificO-glycosylation of MUC1 tandem repeat peptides from secretory mucin of T47D breast cancer cells was analyzed. After affinity isolation on immobilized BC3 antibody, MUC1 was partially deglycosylated by enzymatic treatment with α-sialidase/β-galactosidase and fragmented by proteolytic cleavage with the Arg-C-specific endopeptidase clostripain. The PAP20 glycopeptides were isolated by reversed phase high pressure liquid chromatography and subjected to the structural analyses by quadrupole time-of-flight electrospray ionization mass spectrometry and to the sequencing by Edman degradation. All five positions of the repeat peptide were revealed as O-glycosylation targets in the tumor cell, including the Thr within the DTR motif. The degree of substitution was estimated to average 4.8 glycans per repeat, which compares to 2.6 glycosylated sites per repeat for the mucin from milk (Müller, S., Goletz, S., Packer, N., Gooley, A. A., Lawson, A. M., and Hanisch, F.-G. (1997) J. Biol. Chem.272, 24780–24793). In addition to a modification by glycosylation, the immunodominant DTR motif on T47D-MUC1 is altered by amino acid replacements (PAPGSTAPAAHGVTSAPESR), which were revealed in about 50% of PAP20 peptides. The high incidence of these replacements and their detection also in other cancer cell lines imply that the conserved tandem repeat domain of MUC1 is polymorphic with respect to the peptide sequence. The site-specificO-glycosylation of MUC1 tandem repeat peptides from secretory mucin of T47D breast cancer cells was analyzed. After affinity isolation on immobilized BC3 antibody, MUC1 was partially deglycosylated by enzymatic treatment with α-sialidase/β-galactosidase and fragmented by proteolytic cleavage with the Arg-C-specific endopeptidase clostripain. The PAP20 glycopeptides were isolated by reversed phase high pressure liquid chromatography and subjected to the structural analyses by quadrupole time-of-flight electrospray ionization mass spectrometry and to the sequencing by Edman degradation. All five positions of the repeat peptide were revealed as O-glycosylation targets in the tumor cell, including the Thr within the DTR motif. The degree of substitution was estimated to average 4.8 glycans per repeat, which compares to 2.6 glycosylated sites per repeat for the mucin from milk (Müller, S., Goletz, S., Packer, N., Gooley, A. A., Lawson, A. M., and Hanisch, F.-G. (1997) J. Biol. Chem.272, 24780–24793). In addition to a modification by glycosylation, the immunodominant DTR motif on T47D-MUC1 is altered by amino acid replacements (PAPGSTAPAAHGVTSAPESR), which were revealed in about 50% of PAP20 peptides. The high incidence of these replacements and their detection also in other cancer cell lines imply that the conserved tandem repeat domain of MUC1 is polymorphic with respect to the peptide sequence. Due to the structural complexity of O-linked glycans, this characteristic posttranslational modification of mucin peptides is a polygenic regulated phenomenon and hence is prone to multiple, differentiation-dependent alterations. According to numerous reports, mucin O-glycosylation can now be regarded as a diagnostically relevant indicator of tumor-associated changes that are characterized by 1) the de novo expression of novel glycotopes the ectopic or incompatible expression of carbohydrate blood groups, or 2) by deletion/truncation of glycan chains (1Ho S.B. Kim Y.S. Semin. Cancer Biol. 1991; 2: 389-400PubMed Google Scholar).Also, the widely distributed epithelial mucin MUC1 has been described to be aberrantly processed in cancer cells (2Hull S.R. Bright A. Carraway K.L. Abe M. Hayes D.F. Kufe D.W. Cancer Commun. 1989; 1: 261-267PubMed Google Scholar, 3Hanisch F.-G. Stadie T.R.E. Deutzmann F. Peter-Katalinic J. Eur. J. Biochem. 1996; 236: 318-327Crossref PubMed Scopus (121) Google Scholar, 4Lloyd K. Burchell J. Kudryashov V. Yin B.W.T. Taylor-Papadimitriou J. J. Biol. Chem. 1996; 271: 33325-33334Abstract Full Text Full Text PDF PubMed Scopus (313) Google Scholar). In breast cancer, the nonexpression of the core2 enzyme, Galβ1–3GalNAc/β-6-N-acetylglucosaminyltransferase (5Brockhausen I. Yang J.M. Burchell J.M. Whithouse C. Taylor-Papadimitriou J. Eur. J. Biochem. 1995; 233: 607-617Crossref PubMed Scopus (309) Google Scholar), leads to the truncation of polylactosamine-type chains found on the lactation-associated mucin (6Hanisch F.-G. Uhlenbruck G. Peter-Katalinic J. Egge H. Dabrowski J. Dabrowski U. J. Biol. Chem. 1989; 264: 872-883Abstract Full Text PDF PubMed Google Scholar) and to the accumulation of core-type chains (2Hull S.R. Bright A. Carraway K.L. Abe M. Hayes D.F. Kufe D.W. Cancer Commun. 1989; 1: 261-267PubMed Google Scholar, 3Hanisch F.-G. Stadie T.R.E. Deutzmann F. Peter-Katalinic J. Eur. J. Biochem. 1996; 236: 318-327Crossref PubMed Scopus (121) Google Scholar, 4Lloyd K. Burchell J. Kudryashov V. Yin B.W.T. Taylor-Papadimitriou J. J. Biol. Chem. 1996; 271: 33325-33334Abstract Full Text Full Text PDF PubMed Scopus (313) Google Scholar). The preponderance of sialylated core1-trisaccharide on carcinoma-associated MUC1, which can be regarded as a biosynthetic dead end product, has been shown to originate from the simultaneous up-regulation and overexpression of Galβ1–3GalNAc/α-3-sialyltransferase (7Whitehouse C. Burchell J. Gschmeissner S. Brockhausen I. Lloyd K.O. Taylor-Papadimitriou J. J. Cell Biol. 1997; 137: 1229-1241Crossref PubMed Scopus (93) Google Scholar). Moreover, not only the chain length of the glycans but also their density has been described to be reduced on breast cancer cell-specific MUC1 (4Lloyd K. Burchell J. Kudryashov V. Yin B.W.T. Taylor-Papadimitriou J. J. Biol. Chem. 1996; 271: 33325-33334Abstract Full Text Full Text PDF PubMed Scopus (313) Google Scholar).Reduced glycosylation has been to the to the peptide of the tumor-associated mucin J. Taylor-Papadimitriou J. Cell Biol. 2: Google Scholar). The for to the tumor to of tandem quadrupole electrospray of tandem reversed high pressure liquid quadrupole electrospray of tandem reversed high pressure liquid or to MUC1 is the DTR motif of the repeat peptide Biol. 1997; 1: Scholar). In the to MUC1 a immunodominant motif that the within the repeat C. A. H. F. V. G. M. Eur. J. 1996; Full Text PDF Scopus Google Scholar). revealed that the of to MUC1 to the DTR motif of this is glycosylated with core-type glycans U. C. G. H. S. S. F.-G. Cancer Google Scholar). the of these the sites were with U. C. G. H. S. S. F.-G. Cancer Google were in with the that the immunodominant DTR motif to be to of and that the glycans sites the DTR by glycosylation shown that the within and the Thr within DTR were sites for the from cancer cells I. K. J. Biol. Chem. Full Text PDF PubMed Google Scholar, T.R.E. F.-G. Eur. J. Biochem. 1995; PubMed Scopus Google Scholar) or from milk T.R.E. F.-G. Eur. J. Biochem. 1995; PubMed Scopus Google Scholar), for the to H. Burchell J. Taylor-Papadimitriou J. H. J. Biol. Chem. 1997; PubMed Scopus Google Scholar). on in glycosylation K. J. Biol. Chem. 1996; 271: Full Text Full Text PDF PubMed Scopus Google Scholar) or on of J. H. S. Biochem. J. 1995; PubMed Scopus Google Scholar) were by for isolated MUC1 from milk S. S. F.-G. J. Biol. Chem. 1997; Full Text Full Text PDF PubMed Scopus Google Scholar), and with the that five sites within the tandem repeat of MUC1 were glycosylation on the of O-glycosylation sites within the peptide of tumor-associated MUC1 that is the by T47D breast cancer cell is for breast cancer cells in by expression of (5Brockhausen I. Yang J.M. Burchell J.M. Whithouse C. Taylor-Papadimitriou J. Eur. J. Biochem. 1995; 233: 607-617Crossref PubMed Scopus (309) Google Scholar), by core-type for breast cancer cell lines (4Lloyd K. Burchell J. Kudryashov V. Yin B.W.T. Taylor-Papadimitriou J. J. Biol. Chem. 1996; 271: 33325-33334Abstract Full Text Full Text PDF PubMed Scopus (313) Google Scholar) and of the breast F.-G. Stadie T.R.E. Deutzmann F. Peter-Katalinic J. Eur. J. Biochem. 1996; 236: 318-327Crossref PubMed Scopus (121) Google Scholar), and by of as F.-G. Stadie T.R.E. Deutzmann F. Peter-Katalinic J. Eur. J. Biochem. 1996; 236: 318-327Crossref PubMed Scopus (121) Google Scholar), the DTR motif of the repeat peptide Biol. 1997; 1: Scholar). from mass spectrometry with from Edman were to the glycosylated sites within the of the mucin and to the degree of substitution is the on the site-specificO-glycosylation of a tumor-associated Moreover, for the that of the tandem repeat peptide within the conserved domain of MUC1 the high incidence as the in this can be regarded to of the structural the of immunodominant on MUC1, a mucin with high in tumor from other that MUC1 on breast cancer cells is with epithelial cells (4Lloyd K. Burchell J. Kudryashov V. Yin B.W.T. Taylor-Papadimitriou J. J. Biol. Chem. 1996; 271: 33325-33334Abstract Full Text Full Text PDF PubMed Scopus (313) Google Scholar) and that this reduced substitution of the peptide the DTR motif for the of J. Taylor-Papadimitriou J. Cell Biol. 2: Google Scholar). in this that the breast cancer cell T47D the MUC1 tandem repeat peptide density breast and that the DTR motif is in of the glycosylation of the motif or of as were to a of DTR the motif in a of glycopeptides was with core-type glycans U. C. G. H. S. S. F.-G. Cancer Google Scholar). DTR glycosylated peptides glycosylation of sites U. C. G. H. S. S. F.-G. Cancer Google Scholar). In the of the these from in now to The that tumor cells modification of the motif with glycans the in a of the MUC1 tandem repeat peptide also be altered by the amino acid sites of the DTR motif in T47D-MUC1 are high the of these is a of a on cancer of the can be regarded as 1) the cell T47D is a with respect of MUC1 F.-G. Stadie T.R.E. Deutzmann F. Peter-Katalinic J. Eur. J. Biochem. 1996; 236: 318-327Crossref PubMed Scopus (121) Google Scholar, 4Lloyd K. Burchell J. Kudryashov V. Yin B.W.T. Taylor-Papadimitriou J. J. Biol. Chem. 1996; 271: 33325-33334Abstract Full Text Full Text PDF PubMed Scopus (313) Google Scholar, I. Yang J.M. Burchell J.M. Whithouse C. Taylor-Papadimitriou J. Eur. J. Biochem. 1995; 233: 607-617Crossref PubMed Scopus (309) Google Scholar) and to the of U. J. PubMed Scopus Google Scholar), and 2) MUC1 by T47D The is on of the of which a of of the tandem repeat peptide Biol. 1997; 1: Scholar, F.-G. Biol. PubMed Scopus Google Scholar). is also by the that glycosylation of the repeat peptides within MUC1 is not S. S. F.-G. J. Biol. Chem. 1997; Full Text Full Text PDF PubMed Scopus Google Scholar) but to the of BC3 also of the as and tumor-associated MUC1 Biol. 1997; 1: Scholar). Moreover, BC3 not to the of with to glycosylated DTR U. C. G. H. S. S. F.-G. Cancer Google Scholar), which to the affinity of of the mucin with high density of The of affinity chromatography was by of and a of with The that glycosylated peptides were to proteolytic of glycosylated peptide can be tandem repeat peptides were the be a the density of that glycosylated peptides for the peptides F.-G. S. H. H. H. K. Peter-Katalinic J. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). for glycosylation of within the MUC1 repeat peptide were with in or positions of the glycosylation F.-G. S. H. H. H. K. Peter-Katalinic J. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). The on the and to a and the and a the in glycosylation and tumor-associated of the mucin F.-G. S. H. H. H. K. Peter-Katalinic J. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). In T47D core2 is (6Hanisch F.-G. Uhlenbruck G. Peter-Katalinic J. Egge H. Dabrowski J. Dabrowski U. J. Biol. Chem. 1989; 264: 872-883Abstract Full Text PDF PubMed Google Scholar), and O-glycosylation can to glycan are in the of the in the described which to the DTR was found to the sites H. U. Burchell J. Taylor-Papadimitriou J. G. H. H. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). that the DTR motif is glycosylated in a in the of to the of other but on conserved domain of MUC1 by T47D cells of the of tandem repeat peptide amino acid replacements sites of the replacements to on the degree of glycosylation of the repeat In the DTR not in glycosylation as been from in glycosylation J. Biol. Chem. Full Text PDF PubMed Google Scholar). the of by in the G. Biochem. J. 1991; PubMed Scopus Google Scholar) not glycosylation Thr within the motif. In the for in are in to from in as revealed for the milk mucin S. S. F.-G. J. Biol. Chem. 1997; Full Text Full Text PDF PubMed Scopus Google Scholar). The of the can be estimated to for about 50% of the that not from cell-specific or from cleavage of the conserved In sequencing on the the peptides were was only for a of the conserved domain Taylor-Papadimitriou J. Burchell J. J. Biol. Chem. Full Text PDF PubMed Google Scholar, J. J. Biol. Chem. Full Text PDF PubMed Google Scholar, J. Biol. Chem. Full Text PDF PubMed Google Scholar, M. I. J. J. M. A. I. Eur. J. Biochem. PubMed Scopus Google Scholar). a to of the MUC1 domain from cells with respect to the replacements described in J. Abe M. Hayes Kufe U. S. A. PubMed Scopus Google Scholar). Moreover, from tumor cells revealed the of replacements as in and F.-G. Hanisch, and on not been on of MUC1 repeat peptides from milk S. S. F.-G. J. Biol. Chem. 1997; Full Text Full Text PDF PubMed Scopus Google was on a cell is a to this on other cell lines from the and tumor is in glycosylation which are as secretory in a of breast cancer Due to the structural complexity of O-linked glycans, this characteristic posttranslational modification of mucin peptides is a polygenic regulated phenomenon and hence is prone to multiple, differentiation-dependent alterations. According to numerous reports, mucin O-glycosylation can now be regarded as a diagnostically relevant indicator of tumor-associated changes that are characterized by 1) the de novo expression of novel glycotopes the ectopic or incompatible expression of carbohydrate blood groups, or 2) by deletion/truncation of glycan chains (1Ho S.B. Kim Y.S. Semin. Cancer Biol. 1991; 2: 389-400PubMed Google Scholar). the widely distributed epithelial mucin MUC1 has been described to be aberrantly processed in cancer cells (2Hull S.R. Bright A. Carraway K.L. Abe M. Hayes D.F. Kufe D.W. Cancer Commun. 1989; 1: 261-267PubMed Google Scholar, 3Hanisch F.-G. Stadie T.R.E. Deutzmann F. Peter-Katalinic J. Eur. J. Biochem. 1996; 236: 318-327Crossref PubMed Scopus (121) Google Scholar, 4Lloyd K. Burchell J. Kudryashov V. Yin B.W.T. Taylor-Papadimitriou J. J. Biol. Chem. 1996; 271: 33325-33334Abstract Full Text Full Text PDF PubMed Scopus (313) Google Scholar). In breast cancer, the nonexpression of the core2 enzyme, Galβ1–3GalNAc/β-6-N-acetylglucosaminyltransferase (5Brockhausen I. Yang J.M. Burchell J.M. Whithouse C. Taylor-Papadimitriou J. Eur. J. Biochem. 1995; 233: 607-617Crossref PubMed Scopus (309) Google Scholar), leads to the truncation of polylactosamine-type chains found on the lactation-associated mucin (6Hanisch F.-G. Uhlenbruck G. Peter-Katalinic J. Egge H. Dabrowski J. Dabrowski U. J. Biol. Chem. 1989; 264: 872-883Abstract Full Text PDF PubMed Google Scholar) and to the accumulation of core-type chains (2Hull S.R. Bright A. Carraway K.L. Abe M. Hayes D.F. Kufe D.W. Cancer Commun. 1989; 1: 261-267PubMed Google Scholar, 3Hanisch F.-G. Stadie T.R.E. Deutzmann F. Peter-Katalinic J. Eur. J. Biochem. 1996; 236: 318-327Crossref PubMed Scopus (121) Google Scholar, 4Lloyd K. Burchell J. Kudryashov V. Yin B.W.T. Taylor-Papadimitriou J. J. Biol. Chem. 1996; 271: 33325-33334Abstract Full Text Full Text PDF PubMed Scopus (313) Google Scholar). The preponderance of sialylated core1-trisaccharide on carcinoma-associated MUC1, which can be regarded as a biosynthetic dead end product, has been shown to originate from the simultaneous up-regulation and overexpression of Galβ1–3GalNAc/α-3-sialyltransferase (7Whitehouse C. Burchell J. Gschmeissner S. Brockhausen I. Lloyd K.O. Taylor-Papadimitriou J. J. Cell Biol. 1997; 137: 1229-1241Crossref PubMed Scopus (93) Google Scholar). Moreover, not only the chain length of the glycans but also their density has been described to be reduced on breast cancer cell-specific MUC1 (4Lloyd K. Burchell J. Kudryashov V. Yin B.W.T. Taylor-Papadimitriou J. J. Biol. Chem. 1996; 271: 33325-33334Abstract Full Text Full Text PDF PubMed Scopus (313) Google Scholar). glycosylation has been to the to the peptide of the tumor-associated mucin J. Taylor-Papadimitriou J. Cell Biol. 2: Google Scholar). The for to the tumor to of tandem quadrupole electrospray of tandem reversed high pressure liquid quadrupole electrospray of tandem reversed high pressure liquid or to MUC1 is the DTR motif of the repeat peptide Biol. 1997; 1: Scholar). In the to MUC1 a immunodominant motif that the within the repeat C. A. H. F. V. G. M. Eur. J. 1996; Full Text PDF Scopus Google Scholar). revealed that the of to MUC1 to the DTR motif of this is glycosylated with core-type glycans U. C. G. H. S. S. F.-G. Cancer Google Scholar). the of these the sites were with U. C. G. H. S. S. F.-G. Cancer Google Scholar). were in with the that the immunodominant DTR motif to be to of and that the glycans sites the DTR by glycosylation shown that the within and the Thr within DTR were sites for the from cancer cells I. K. J. Biol. Chem. Full Text PDF PubMed Google Scholar, T.R.E. F.-G. Eur. J. Biochem. 1995; PubMed Scopus Google Scholar) or from milk T.R.E. F.-G. Eur. J. Biochem. 1995; PubMed Scopus Google Scholar), for the to H. Burchell J. Taylor-Papadimitriou J. H. J. Biol. Chem. 1997; PubMed Scopus Google Scholar). on in glycosylation K. J. Biol. Chem. 1996; 271: Full Text Full Text PDF PubMed Scopus Google Scholar) or on of J. H. S. Biochem. J. 1995; PubMed Scopus Google Scholar) were by for isolated MUC1 from milk S. S. F.-G. J. Biol. Chem. 1997; Full Text Full Text PDF PubMed Scopus Google Scholar), and with the that five sites within the tandem repeat of MUC1 were glycosylation on the of O-glycosylation sites within the peptide of tumor-associated MUC1 that is the by T47D breast cancer cell is for breast cancer cells in by expression of (5Brockhausen I. Yang J.M. Burchell J.M. Whithouse C. Taylor-Papadimitriou J. Eur. J. Biochem. 1995; 233: 607-617Crossref PubMed Scopus (309) Google Scholar), by core-type for breast cancer cell lines (4Lloyd K. Burchell J. Kudryashov V. Yin B.W.T. Taylor-Papadimitriou J. J. Biol. Chem. 1996; 271: 33325-33334Abstract Full Text Full Text PDF PubMed Scopus (313) Google Scholar) and of the breast F.-G. Stadie T.R.E. Deutzmann F. Peter-Katalinic J. Eur. J. Biochem. 1996; 236: 318-327Crossref PubMed Scopus (121) Google Scholar), and by of as F.-G. Stadie T.R.E. Deutzmann F. Peter-Katalinic J. Eur. J. Biochem. 1996; 236: 318-327Crossref PubMed Scopus (121) Google Scholar), the DTR motif of the repeat peptide Biol. 1997; 1: Scholar). from mass spectrometry with from Edman were to the glycosylated sites within the of the mucin and to the degree of substitution is the on the site-specificO-glycosylation of a tumor-associated Moreover, for the that of the tandem repeat peptide within the conserved domain of MUC1 the high incidence as the sequence. in this can be regarded to of the structural the of immunodominant on MUC1, a mucin with high in tumor from other that MUC1 on breast cancer cells is with epithelial cells (4Lloyd K. Burchell J. Kudryashov V. Yin B.W.T. Taylor-Papadimitriou J. J. Biol. Chem. 1996; 271: 33325-33334Abstract Full Text Full Text PDF PubMed Scopus (313) Google Scholar) and that this reduced substitution of the peptide the DTR motif for the of J. Taylor-Papadimitriou J. Cell Biol. 2: Google Scholar). in this that the breast cancer cell T47D the MUC1 tandem repeat peptide density breast and that the DTR motif is in of the glycosylation of the motif or of as were to a of DTR the motif in a of glycopeptides was with core-type glycans U. C. G. H. S. S. F.-G. Cancer Google Scholar). DTR glycosylated peptides glycosylation of sites U. C. G. H. S. S. F.-G. Cancer Google Scholar). In the of the these from in now to The that tumor cells modification of the motif with glycans the in a of the MUC1 tandem repeat peptide also be altered by the amino acid sites of the DTR motif in T47D-MUC1 are high the of these is a of a on cancer of the can be regarded as 1) the cell T47D is a with respect of MUC1 F.-G. Stadie T.R.E. Deutzmann F. Peter-Katalinic J. Eur. J. Biochem. 1996; 236: 318-327Crossref PubMed Scopus (121) Google Scholar, 4Lloyd K. Burchell J. Kudryashov V. Yin B.W.T. Taylor-Papadimitriou J. J. Biol. Chem. 1996; 271: 33325-33334Abstract Full Text Full Text PDF PubMed Scopus (313) Google Scholar, I. Yang J.M. Burchell J.M. Whithouse C. Taylor-Papadimitriou J. Eur. J. Biochem. 1995; 233: 607-617Crossref PubMed Scopus (309) Google Scholar) and to the of U. J. PubMed Scopus Google Scholar), and 2) MUC1 by T47D The is on of the of which a of of the tandem repeat peptide Biol. 1997; 1: Scholar, F.-G. Biol. PubMed Scopus Google Scholar). is also by the that glycosylation of the repeat peptides within MUC1 is not S. S. F.-G. J. Biol. Chem. 1997; Full Text Full Text PDF PubMed Scopus Google Scholar) but to the of BC3 also of the as and tumor-associated MUC1 Biol. 1997; 1: Scholar). Moreover, BC3 not to the of with to glycosylated DTR U. C. G. H. S. S. F.-G. Cancer Google Scholar), which to the affinity of of the mucin with high density of The of affinity chromatography was by of and a of with The that glycosylated peptides were to proteolytic of glycosylated peptide can be tandem repeat peptides were the be a the density of that glycosylated peptides for the peptides F.-G. S. H. H. H. K. Peter-Katalinic J. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). for glycosylation of within the MUC1 repeat peptide were with in or positions of the glycosylation F.-G. S. H. H. H. K. Peter-Katalinic J. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). The on the and to a and the and a the in glycosylation and tumor-associated of the mucin F.-G. S. H. H. H. K. Peter-Katalinic J. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). In T47D core2 is (6Hanisch F.-G. Uhlenbruck G. Peter-Katalinic J. Egge H. Dabrowski J. Dabrowski U. J. Biol. Chem. 1989; 264: 872-883Abstract Full Text PDF PubMed Google Scholar), and O-glycosylation can to glycan are in the of the in the described which to the DTR was found to the sites H. U. Burchell J. Taylor-Papadimitriou J. G. H. H. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). that the DTR motif is glycosylated in a in the of to the of other but on conserved domain of MUC1 by T47D cells of the of tandem repeat peptide amino acid replacements sites of the replacements to on the degree of glycosylation of the repeat In the DTR not in glycosylation as been from in glycosylation J. Biol. Chem. Full Text PDF PubMed Google Scholar). the of by in the G. Biochem. J. 1991; PubMed Scopus Google Scholar) not glycosylation Thr within the motif. In the for in are in to from in as revealed for the milk mucin S. S. F.-G. J. Biol. Chem. 1997; Full Text Full Text PDF PubMed Scopus Google Scholar). The of the can be estimated to for about 50% of the that not from cell-specific or from cleavage of the conserved In sequencing on the the peptides were was only for a of the conserved domain Taylor-Papadimitriou J. Burchell J. J. Biol. Chem. Full Text PDF PubMed Google Scholar, J. J. Biol. Chem. Full Text PDF PubMed Google Scholar, J. Biol. Chem. Full Text PDF PubMed Google Scholar, M. I. J. J. M. A. I. Eur. J. Biochem. PubMed Scopus Google Scholar). a to of the MUC1 domain from cells with respect to the replacements described in J. Abe M. Hayes Kufe U. S. A. PubMed Scopus Google Scholar). Moreover, from tumor cells revealed the of replacements as in and F.-G. Hanisch, and on not been on of MUC1 repeat peptides from milk S. S. F.-G. J. Biol. Chem. 1997; Full Text Full Text PDF PubMed Scopus Google was on a cell is a to this on other cell lines from the and tumor is in glycosylation which are as secretory in a of breast cancer in this can be regarded to of the structural the of immunodominant on MUC1, a mucin with high in tumor from other that MUC1 on breast cancer cells is with epithelial cells (4Lloyd K. Burchell J. Kudryashov V. Yin B.W.T. Taylor-Papadimitriou J. J. Biol. Chem. 1996; 271: 33325-33334Abstract Full Text Full Text PDF PubMed Scopus (313) Google Scholar) and that this reduced substitution of the peptide the DTR motif for the of J. Taylor-Papadimitriou J. Cell Biol. 2: Google Scholar). in this that the breast cancer cell T47D the MUC1 tandem repeat peptide density breast and that the DTR motif is in of the glycosylation of the motif or of as were to a of DTR the motif in a of glycopeptides was with core-type glycans U. C. G. H. S. S. F.-G. Cancer Google Scholar). DTR glycosylated peptides glycosylation of sites U. C. G. H. S. S. F.-G. Cancer Google Scholar). In the of the these from in now to The that tumor cells modification of the motif with glycans the in a of the MUC1 tandem repeat peptide also be altered by the amino acid sites of the DTR motif in T47D-MUC1 are high the of these is a of a on cancer of the The can be regarded as 1) the cell T47D is a with respect of MUC1 F.-G. Stadie T.R.E. Deutzmann F. Peter-Katalinic J. Eur. J. Biochem. 1996; 236: 318-327Crossref PubMed Scopus (121) Google Scholar, 4Lloyd K. Burchell J. Kudryashov V. Yin B.W.T. Taylor-Papadimitriou J. J. Biol. Chem. 1996; 271: 33325-33334Abstract Full Text Full Text PDF PubMed Scopus (313) Google Scholar, I. Yang J.M. Burchell J.M. Whithouse C. Taylor-Papadimitriou J. Eur. J. Biochem. 1995; 233: 607-617Crossref PubMed Scopus (309) Google Scholar) and to the of U. J. PubMed Scopus Google Scholar), and 2) MUC1 by T47D The is on of the of which a of of the tandem repeat peptide Biol. 1997; 1: Scholar, F.-G. Biol. PubMed Scopus Google Scholar). is also by the that glycosylation of the repeat peptides within MUC1 is not S. S. F.-G. J. Biol. Chem. 1997; Full Text Full Text PDF PubMed Scopus Google Scholar) but to the of BC3 also of the as and tumor-associated MUC1 Biol. 1997; 1: Scholar). Moreover, BC3 not to the of with to glycosylated DTR U. C. G. H. S. S. F.-G. Cancer Google Scholar), which to the affinity of of the mucin with high density of The of affinity chromatography was by of and a of with The that glycosylated peptides were to proteolytic of glycosylated peptide can be tandem repeat peptides were the be a the density of that glycosylated peptides for the peptides F.-G. S. H. H. H. K. Peter-Katalinic J. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). for glycosylation of within the MUC1 repeat peptide were with in or positions of the glycosylation F.-G. S. H. H. H. K. Peter-Katalinic J. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). The on the and to a and the and a the in glycosylation and tumor-associated of the mucin F.-G. S. H. H. H. K. Peter-Katalinic J. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). In T47D core2 is (6Hanisch F.-G. Uhlenbruck G. Peter-Katalinic J. Egge H. Dabrowski J. Dabrowski U. J. Biol. Chem. 1989; 264: 872-883Abstract Full Text PDF PubMed Google Scholar), and O-glycosylation can to glycan are in the of the in the described which to the DTR was found to the sites H. U. Burchell J. Taylor-Papadimitriou J. G. H. H. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). that the DTR motif is glycosylated in a in the of to the of other but on The conserved domain of MUC1 by T47D cells of the of tandem repeat peptide amino acid replacements sites of the replacements to on the degree of glycosylation of the repeat In the DTR not in glycosylation as been from in glycosylation J. Biol. Chem. Full Text PDF PubMed Google Scholar). the of by in the G. Biochem. J. 1991; PubMed Scopus Google Scholar) not glycosylation Thr within the motif. In the for in are in to from in as revealed for the milk mucin S. S. F.-G. J. Biol. Chem. 1997; Full Text Full Text PDF PubMed Scopus Google Scholar). The of the can be estimated to for about 50% of the that not from cell-specific or from cleavage of the conserved In sequencing on the the peptides were was only for a of the conserved domain Taylor-Papadimitriou J. Burchell J. J. Biol. Chem. Full Text PDF PubMed Google Scholar, J. J. Biol. Chem. Full Text PDF PubMed Google Scholar, J. Biol. Chem. Full Text PDF PubMed Google Scholar, M. I. J. J. M. A. I. Eur. J. Biochem. PubMed Scopus Google Scholar). a to of the MUC1 domain from cells with respect to the replacements described in J. Abe M. Hayes Kufe U. S. A. PubMed Scopus Google Scholar). Moreover, from tumor cells revealed the of replacements as in and F.-G. Hanisch, and on not been on of MUC1 repeat peptides from milk S. S. F.-G. J. Biol. Chem. 1997; Full Text Full Text PDF PubMed Scopus Google Scholar). was on a cell is a to this on other cell lines from the and tumor is in glycosylation which are as secretory in a of breast cancer