The Translational Regulation of Lipoprotein Lipase in Diabetic Rats Involves the 3′-Untranslated Region of the Lipoprotein Lipase mRNA

Adipose tissue lipoprotein lipase (LPL) activity is decreased in patients with poorly controlled diabetes, and this contributes to the dyslipidemia of diabetes. To study the mechanism of this decrease in LPL, we studied adipose tissue LPL expression in male rats with streptozotocin-induced diabetes. Heparin releasable and extractable LPL activity in the epididymal fat decreased by 75–80% in the diabetic group and treatment of the rats with insulin prior to sacrifice reversed this effect. Northern blot analysis indicated no corresponding change in LPL mRNA levels. However, LPL synthetic rate, measured using 35Smethionine pulse labeling, was decreased by 75% in the diabetic adipocytes, and insulin treatment reversed this effect. These results suggested regulation of LPL at the level of translation. Diabetic adipocytes demonstrated no change in the distribution of LPL mRNA associated with polysomes, suggesting no inhibition of translation initiation. Addition of cytoplasmic extracts from control and diabetic adipocytes to a reticulocyte lysate system demonstrated the inhibition of LPL translation in vitro. Using different LPL mRNA transcripts in this in vitro translation assay, we found that the 3′-untranslated region (UTR) of the LPL mRNA was important in controlling translation inhibition by the cytoplasmic extracts. To identify the specific region involved, gel shift analysis was performed. A specific shift in mobility was observed when diabetic cytoplasmic extract was added to a transcript containing nucleotides 1818–2000 of the LPL 3′-UTR. Thus, inhibition of translation is the predominant mechanism for the decreased adipose tissue LPL in this insulin-deficient model of diabetes. Translation inhibition involves the interaction of a cytoplasmic factor, probably an RNA-binding protein, with specific sequences of the LPL 3′-UTR. Adipose tissue lipoprotein lipase (LPL) activity is decreased in patients with poorly controlled diabetes, and this contributes to the dyslipidemia of diabetes. To study the mechanism of this decrease in LPL, we studied adipose tissue LPL expression in male rats with streptozotocin-induced diabetes. Heparin releasable and extractable LPL activity in the epididymal fat decreased by 75–80% in the diabetic group and treatment of the rats with insulin prior to sacrifice reversed this effect. Northern blot analysis indicated no corresponding change in LPL mRNA levels. However, LPL synthetic rate, measured using 35Smethionine pulse labeling, was decreased by 75% in the diabetic adipocytes, and insulin treatment reversed this effect. These results suggested regulation of LPL at the level of translation. Diabetic adipocytes demonstrated no change in the distribution of LPL mRNA associated with polysomes, suggesting no inhibition of translation initiation. Addition of cytoplasmic extracts from control and diabetic adipocytes to a reticulocyte lysate system demonstrated the inhibition of LPL translation in vitro. Using different LPL mRNA transcripts in this in vitro translation assay, we found that the 3′-untranslated region (UTR) of the LPL mRNA was important in controlling translation inhibition by the cytoplasmic extracts. To identify the specific region involved, gel shift analysis was performed. A specific shift in mobility was observed when diabetic cytoplasmic extract was added to a transcript containing nucleotides 1818–2000 of the LPL 3′-UTR. Thus, inhibition of translation is the predominant mechanism for the decreased adipose tissue LPL in this insulin-deficient model of diabetes. Translation inhibition involves the interaction of a cytoplasmic factor, probably an RNA-binding protein, with specific sequences of the LPL 3′-UTR. lipoprotein lipase untranslated region control rats diabetic rats diabetic rats treated with insulin polyacrylamide gel electrophoresis reverse-transcription polymerase chain reaction Lipoprotein lipase (LPL)1 hydrolyzes the core of triglyceride-rich lipoproteins (chylomicrons and very low density lipoprotein) into free fatty acids and monoacylglycerol, facilitating the removal of triglyceride-rich lipoproteins from the bloodstream. Patients with diabetes, especially insulin-deficient diabetes, often manifest a decrease in adipose tissue LPL activity, and this is accompanied by an increase in plasma triglycerides (1Taskinen M.R. Diabetes Metab. Rev. 1987; 3: 551-570Crossref PubMed Scopus (210) Google Scholar). With insulin treatment, there is an improvement in both LPL activity and triglycerides (2Pfeifer M.A. Brunzell J.D. Best J.D. Judzewitsch R.G. Halter J.B. Porte Jr., D. Diabetes. 1983; 32: 525-531Crossref PubMed Google Scholar, 3Simsolo R.B. Ong J.M. Saffari B. Kern P.A. J. Lipid Res. 1992; 33: 89-95Abstract Full Text PDF PubMed Google Scholar). The regulation of LPL activity is closely linked to insulin levels and nutritional state, as demonstrated by the changes in LPL during cycles of feeding and fasting (4Eckel R.H. Borensztajn J. Lipoprotein Lipase. Evener, Chicago1987: 79-132Google Scholar, 5Doolittle M.H. Ben-Zeev O. Elovson J. Martin D. Kirchgessner T.G. J. Biol. Chem. 1990; 265: 4570-4577Abstract Full Text PDF PubMed Google Scholar, 6Ong J.M. Kern P.A. J. Clin. Invest. 1989; 84: 305-311Crossref PubMed Scopus (120) Google Scholar). Both in rat models of diabetes and human diabetes, the use of drugs to improve diabetes control resulted in increased adipose tissue LPL activity (1Taskinen M.R. Diabetes Metab. Rev. 1987; 3: 551-570Crossref PubMed Scopus (210) Google Scholar, 7Taskinen M.-R. Nikkilä E.A. Diabetologia. 1979; 17: 351-357Crossref PubMed Scopus (107) Google Scholar, 8Pykalisto O. Smith P.H. Brunzell J.D. J. Clin. Invest. 1975; 56: 1108-1116Crossref PubMed Scopus (229) Google Scholar). However, recent studies demonstrated that the treatment of diabetes resulted in increases in LPL protein and LPL synthesis with no change in LPL mRNA levels, suggesting posttranscriptional regulation, possibly at the level of LPL translation (3Simsolo R.B. Ong J.M. Saffari B. Kern P.A. J. Lipid Res. 1992; 33: 89-95Abstract Full Text PDF PubMed Google Scholar, 9Tavangar K. Murata Y. Pedersen M.E. Goers J.F. Hoffman A.R. Kraemer F.B. J. Clin. Invest. 1992; 90: 1672-1678Crossref PubMed Scopus (53) Google Scholar). Translational regulation has been identified as an important mechanism for the regulation of LPL in response to catecholamines and thyroid hormone (10Yukht A. Davis R.C. Ong J.M. Ranganathan G. Kern P.A. J. Clin. Invest. 1995; 96: 2438-2444Crossref PubMed Scopus (35) Google Scholar, 11Kern P.A. Ranganathan G. Yukht A. Ong J.M. Davis R. J. Lipid Res. 1996; 37: 2332-2340Abstract Full Text PDF PubMed Google Scholar). In response to catecholamines, cultured adipocytes demonstrate a 4-fold decrease in LPL synthesis mediated by the presence of a RNA-binding protein, which interacts with a region on the proximal 3′-UTR of LPL mRNA (12Ranganathan G. Vu D. Kern P.A. J. Biol. Chem. 1997; 272: 2515-2519Abstract Full Text Full Text PDF PubMed Scopus (35) Google Scholar). Hypothyroid rats demonstrate an increase in LPL translation, and this is thought to be related to the absence of the RNA-binding protein that binds to the same region (11Kern P.A. Ranganathan G. Yukht A. Ong J.M. Davis R. J. Lipid Res. 1996; 37: 2332-2340Abstract Full Text PDF PubMed Google Scholar). The expression of many other genes is regulated by translation, and this can occur through RNA-binding proteins that bind to specific regions of either the 5′- or 3′-UTRs of the mRNA, and interfere with translation (13Wormington M. Bioessays. 1994; 16: 533-535Crossref PubMed Scopus (43) Google Scholar, 14Kozak M. Gene ( Amst. ). 1999; 234: 187-208Crossref PubMed Scopus (1144) Google Scholar). We have studied the mechanism involved in the regulation of LPL activity in the adipose tissue of diabetic rats. This inhibition of LPL activity was accompanied by a corresponding decrease in LPL synthetic rate with no significant change in LPL mRNA. To further characterize the mechanism involved, we made cytoplasmic extracts from adipocytes and studied the effect of cytoplasmic trans-acting factors on translation of various LPL constructs. We have identified a region of the 3′-UTR of LPL mRNA that is involved in an RNA protein interactions, resulting in inhibition of LPL translation in diabetes. Male Harlan Sprague-Dawley rats (175–200 g) were purchased from Harlan Sprague-Dawley (Indianapolis, IN). Three groups of rats were used in these studies: control (C) rats, diabetic (D) rats, and diabetic rats that were treated with insulin (DI). The rats were made diabetic by tail veil injection of Streptozotocin (60 mg/kg body weight) dissolved in 50 mm citrate buffer, pH 4.5. Control rats were injected with the same volume of buffer. Insulin-treated diabetic rats were treated identically to the diabetic rats except that they received 8 units of neutral protamine Hagedorn human insulin subcutaneously on each of the last 2 days before sacrifice. All the animals were sacrificed 14 days after streptozotocin injection. At the time of sacrifice, blood glucose levels in the diabetic group were greater than 375 mg/dl, insulin-treated diabetic rats were higher than the control but considerably lower than the diabetic group (Table I). The epididymal fat pads were immediately removed and processed as described below.Table IEffect of diabetes and insulin treatment on LPL activityLPL activityGlucoseHeparin releasedExtractednmol/min/106cellsmg%C22 ± 0.422 ± 6.0109 ± 5D3.2 ± 0.81-ap < 0.01 versus control.5.9 ± 1.01-ap < 0.01 versus control.405 ± 241-ap < 0.01 versus control.DI73 ± 121-ap < 0.01 versus control.34 ± 7.01-ap < 0.01 versus control.165 ± 71-ap < 0.01 versus control.All data are expressed as mean ± S.E., n = 10–12 for each group.1-a p < 0.01 versus control. Open table in a new tab All data are expressed as mean ± S.E., n = 10–12 for each group. Heparin releasable and extractable LPL activities were determined (15Kern P.A. Marshall S. Eckel R.H. J. Clin. Invest. 1985; 75: 199-208Crossref PubMed Scopus (35) Google Scholar). To measure heparin releasable LPL, 100 mg of minced adipose tissue was incubated in 1 ml of Dulbecco's modified Eagle's medium containing 10 units/ml heparin for 45 min at 37 °C. After collecting the heparin released fraction, tissue LPL was extracted in 50 mmphosphate-buffered saline, pH 7.4, containing 1% Triton X-100, 0.1% SDS, and 0.5% deoxycholate, as described previously (6Ong J.M. Kern P.A. J. Clin. Invest. 1989; 84: 305-311Crossref PubMed Scopus (120) Google Scholar). LPL catalytic activity was measured as described previously (16Nilsson-Ehle P. Schotz M.C. J. Lipid Res. 1976; 17: 536-541Abstract Full Text PDF PubMed Google Scholar), using a substrate containing 3Htriolein and human serum as a source of apoC-II. LPL activity was expressed as nanomoles of free fatty acid released per minute per 106 cells. Cell number was determined using the method of DiGirolamo (17DiGirolamo M. Mendlinger S. Fertig J.W. Am. J. Physiol. 1971; 221: 850-858Crossref PubMed Scopus (272) Google Scholar). The synthetic rate of LPL was measured in adipocytes using a 30-min pulse with 35Smethionine (100 μCi/ml), as described previously (18Ong J.M. Kirchgessner T.G. Schotz M.C. Kern P.A. J. Biol. Chem. 1988; 263: 12933-12938Abstract Full Text PDF PubMed Google Scholar). Previous studies have demonstrated the linearity of 35Smethionine incorporation into adipocytes for up to 90 min in the presence and absence of insulin and thyroid hormone (18Ong J.M. Kirchgessner T.G. Schotz M.C. Kern P.A. J. Biol. Chem. 1988; 263: 12933-12938Abstract Full Text PDF PubMed Google Scholar, 19Saffari B. Ong J.M. Kern P.A. J. Lipid Res. 1992; 33: 241-249Abstract Full Text PDF PubMed Google Scholar). The unincorporated label was aspirated, and the total cellular proteins were extracted in lysis buffer containing 50 mm phosphate buffer, pH 7.4, 2% deoxycholate, 1% SDS, 20 mm phenylmethylsulfonyl fluoride, 2 mm leupeptin, and 2 mm EDTA. The extracts were immunoprecipitated using specific polyclonal antibodies as described previously (20Goers J.F. Petersen M.E. Kern P.A. Ong J. Schotz M.C. Anal. Biochem. 1987; 166: 27-35Crossref PubMed Scopus (60) Google Scholar). Immunoprecipitated samples were analyzed on 10% SDS-PAGE followed by autoradiography. RNA was extracted from adipocytes using the method of Chomczynski and Sacchi (21Chomczynski P. Sacchi N. Anal. Biochem. 1987; 162: 156-159Crossref PubMed Scopus (63388) Google Scholar). Equal amounts of total RNA from the various treatment groups were analyzed using 2.2 m formaldehyde, 1% agarose gels. Northern blots were probed using 32PdCTP-labeled human LPL (22Holm C. Kirchgessner T.G. Svenson K.L. G. S. C. P. Schotz M.C. 1988; PubMed Scopus Google and followed by autoradiography. The of the was using the and analysis and the of mRNA was were as described previously (10Yukht A. Davis R.C. Ong J.M. Ranganathan G. Kern P.A. J. Clin. Invest. 1995; 96: 2438-2444Crossref PubMed Scopus (35) Google Scholar, J. S. A. 1987; 84: PubMed Scopus Google Scholar). were from adipocytes from control and diabetic rats. extracts were with and were at for at °C. To demonstrate the of LPL mRNA into the free fraction, 1 mm was added to a control were in and were by at was and RNA was of LPL mRNA levels in each was using as described previously J.M. R.B. M. A. Kern P.A. J. Lipid Res. 1994; Full Text PDF PubMed Google Scholar). The for this reaction were from the LPL and the was nucleotides and the was nucleotides T.G. Svenson K.L. Schotz M.C. J. Biol. Chem. 1987; Full Text PDF PubMed Google Scholar). volume of each of was followed by for cycles at °C. The resulting gel was using an and analyzed using the was from adipocytes from and insulin-treated diabetic rats, as described previously (10Yukht A. Davis R.C. Ong J.M. Ranganathan G. Kern P.A. J. Clin. Invest. 1995; 96: 2438-2444Crossref PubMed Scopus (35) Google Scholar, J. Biol. Chem. 1989; Full Text PDF PubMed Google Scholar). were in 2 of lysis buffer pH 7.4, mm mm 10 mm mm mm using 10 of a were at for min at and the extract was used to by at for min on were using and the proteins were and A mm pH 7.4, 20 mm mm mm and 10% Equal of cytoplasmic extracts of were used to on in vitro translation using the reticulocyte lysate system 2 in is described by K.L. Kirchgessner T.G. Schotz M.C. 1987; PubMed Scopus Google Scholar). nucleotides of the and nucleotides of the 3′-UTR of 1 is to 2 except that the 3′-UTR up to the at as described G. Ong J.M. Yukht A. M. R.B. A. Kern P.A. J. Biol. Chem. 1995; Full Text Full Text PDF PubMed Scopus Google Scholar). was made by 2 described RNA transcripts from human LPL were used for in vitro translation as described previously (12Ranganathan G. Vu D. Kern P.A. J. Biol. Chem. 1997; 272: 2515-2519Abstract Full Text Full Text PDF PubMed Scopus (35) Google Scholar). was with a to a transcript of the was RNA transcripts were using a reticulocyte lysate system in the presence of 35Smethionine for extracts from adipocytes were added to the in The translation reaction were analyzed by SDS-PAGE and autoradiography. were using with a added to the corresponding to LPL nucleotides and The were on agarose and used to transcript using RNA polymerase RNA was in the presence of 10 1 mm and mm were using and shift analysis was as described previously E.A. S. A. 1988; PubMed Scopus Google Scholar). transcript was incubated with extracts of from adipocytes at for 20 min in the presence of and buffer containing 20 mm pH 7.4, 50 10% and 1 mm Heparin was added to a of and was for an 10 were on polyacrylamide in m m m and analyzed by autoradiography. were sacrificed 14 days after streptozotocin injection. the blood glucose and adipose tissue LPL activity in the groups of rats. diabetes results in and a in fat LPL activity data were expressed per 106 (Table I). glucose was mg in the rats, and LPL activity was decreased 75% versus C. In the rats, blood glucose was lower than in the rats, with C. However, in the group of rats, LPL activity was and was higher than in the especially in the heparin released To study the mechanism of regulation by diabetes and insulin treatment, LPL mRNA levels and LPL synthetic rate were To LPL synthetic rate, adipocytes from and rats were with 35Smethionine followed by of in there was a 75% inhibition of LPL synthesis in the from diabetic rat adipose LPL synthetic rate in the adipocytes was to that in control To LPL mRNA levels, Northern blots were on the adipocytes from and rats. expressed as the LPL mRNA in the rat adipose tissue was no different from LPL mRNA in the adipose tissue 1 In a the mRNA in the adipocytes was different from the group 1 Thus, these data that changes in LPL activity can be by changes in LPL synthesis and are in changes in LPL mRNA. These data that the of regulation is at the level of LPL translation. mechanism of regulation involves the interaction of factors with the to the of mRNA from the and an inhibition of J.B. ( ). 1990; PubMed Scopus Google Scholar). To a mechanism with LPL, we studied the distribution of LPL mRNA on from and rat in we no change in the distribution of LPL mRNA associated with the In both and rat adipose of LPL mRNA was associated with polysomes, suggesting that the was be involved in the for regulation by proteins is the which is involved in the regulation of LPL by catecholamines (10Yukht A. Davis R.C. Ong J.M. Ranganathan G. Kern P.A. J. Clin. Invest. 1995; 96: 2438-2444Crossref PubMed Scopus (35) Google Scholar). To a mechanism is involved with diabetes, we cytoplasmic extracts from control and diabetic rat adipocytes as described and and added these extracts to a reticulocyte lysate in vitro translation system containing LPL cytoplasmic factors were in the extracts that to the LPL transcript and regulated translation, we to a change in LPL translation by the reticulocyte lysate In this in vitro translation we used different of these the and The the LPL mRNA up to the on the 3′-UTR K.L. Kirchgessner T.G. Schotz M.C. 1987; PubMed Scopus Google Scholar). The and of the 3′-UTR of the LPL mRNA and at and in translation of 1 and 2 was by the of diabetic extracts. there was inhibition of LPL translation by the control as described by previously (11Kern P.A. Ranganathan G. Yukht A. Ong J.M. Davis R. J. Lipid Res. 1996; 37: 2332-2340Abstract Full Text PDF PubMed Google Scholar), the diabetic extract LPL translation in 1 and However, which at was by the of the that an was with a on the 3′-UTR To further for the interaction of a protein with the LPL we gel described and RNA transcripts were made to of LPL 3′-UTR the region nucleotides and of the region is at Equal amounts of extract from and adipose tissue were added to each of the RNA sequences were corresponding to LPL nucleotides and RNA transcripts and no with the diabetic adipose RNA transcript corresponding to nucleotides a with the diabetic extract which a mobility shift Addition of the extract a mobility the was with the same of extract protein, a decrease in of To demonstrate the of this we added an of transcript in an of transcript corresponding to nucleotides 1818–2000 the gel the of an of RNA transcript for Lipoprotein lipase is a in and the adipose tissue is important in the regulation of plasma levels and in the of adipose tissue A. 1999; PubMed Scopus Google Scholar, R. 1997; PubMed Scopus Google Scholar). The regulation of LPL in adipose tissue is and at cellular S. J.M. PubMed Scopus Google Scholar). is an important of adipose tissue LPL, but the mechanism of regulation by insulin is on the and system in and rats LPL activity is increased in the state, and this increase is to increased LPL M.H. Ben-Zeev O. Elovson J. Martin D. Kirchgessner T.G. J. Biol. Chem. 1990; 265: 4570-4577Abstract Full Text PDF PubMed Google Scholar, 6Ong J.M. Kern P.A. J. Clin. Invest. 1989; 84: 305-311Crossref PubMed Scopus (120) Google Scholar). in LPL activity are accompanied by increases in LPL mRNA levels in other models S. J. G. Gene ( Amst. ). 1988; PubMed Scopus Google Scholar). In vitro studies of the effect of insulin on LPL in adipocytes have demonstrated increases in LPL mRNA levels in rat (18Ong J.M. Kirchgessner T.G. Schotz M.C. Kern P.A. J. Biol. Chem. 1988; 263: 12933-12938Abstract Full Text PDF PubMed Google and increased posttranscriptional in adipocytes M. J. J. Biol. Chem. 1989; Full Text PDF PubMed Google Scholar). Patients with both 1 and 2 diabetes manifest decreased adipose LPL activity, which increases treatment of the diabetes (2Pfeifer M.A. Brunzell J.D. Best J.D. Judzewitsch R.G. Halter J.B. Porte Jr., D. Diabetes. 1983; 32: 525-531Crossref PubMed Google Scholar, 3Simsolo R.B. Ong J.M. Saffari B. Kern P.A. J. Lipid Res. 1992; 33: 89-95Abstract Full Text PDF PubMed Google Scholar, 7Taskinen M.-R. Nikkilä E.A. Diabetologia. 1979; 17: 351-357Crossref PubMed Scopus (107) Google Scholar, 8Pykalisto O. Smith P.H. Brunzell J.D. J. Clin. Invest. 1975; 56: 1108-1116Crossref PubMed Scopus (229) Google Scholar). In this increase in LPL activity was accompanied by an increase in mRNA levels, but was associated with an increase in LPL protein and synthetic rate (3Simsolo R.B. Ong J.M. Saffari B. Kern P.A. J. Lipid Res. 1992; 33: 89-95Abstract Full Text PDF PubMed Google Scholar). were made in rats, which were diabetic with streptozotocin K. Murata Y. Pedersen M.E. Goers J.F. Hoffman A.R. Kraemer F.B. J. Clin. Invest. 1992; 90: 1672-1678Crossref PubMed Scopus (53) Google Scholar). these data suggested a mechanism of regulation, we the regulation of LPL by streptozotocin-induced diabetes in greater LPL activity was decreased in the rats with the and rats. the rats demonstrated LPL activity that was higher than that of the control rats, which to the rate of new LPL synthesis and that accompanied the of were observed previously K. Murata Y. Pedersen M.E. Goers J.F. Hoffman A.R. Kraemer F.B. J. Clin. Invest. 1992; 90: 1672-1678Crossref PubMed Scopus (53) Google Scholar). the adipose of these rats were for LPL there were changes in LPL mRNA levels changes in LPL activity, that the changes in LPL activity be on the changes in LPL the other the changes in LPL on 35Smethionine labeling, closely the changes in LPL activity the and rats. The increase in LPL activity in the rats with be for by the increase in mRNA and the increase in LPL synthetic rate, suggesting that regulation was as has been described previously in other M.H. Ben-Zeev O. Elovson J. Martin D. Kirchgessner T.G. J. Biol. Chem. 1990; 265: 4570-4577Abstract Full Text PDF PubMed Google Scholar). these data that regulation is the of LPL regulation in this of insulin Translational regulation of protein synthesis can occur through the of trans-acting proteins and can sequences on either the or 3′-UTR of the mRNA M. Gene ( Amst. ). 1999; 234: 187-208Crossref PubMed Scopus (1144) Google Scholar). of the has been described in the regulation of translation, the of a trans-acting protein to the resulted in the of mRNA from the E.A. S. A. 1988; PubMed Scopus Google Scholar, J.B. ( ). 1990; PubMed Scopus Google Scholar). To this mechanism in we an analysis of from control and diabetic We found no change in the distribution of LPL mRNA with the polysomes, suggesting that the regulation was to a change in of translation. Translational regulation can occur through of factors with the 3′-UTR (13Wormington M. Bioessays. 1994; 16: 533-535Crossref PubMed Scopus (43) Google Scholar, P. 1990; Scopus Google Scholar). We previously the of trans-acting proteins that LPL translation by to the proximal 3′-UTR nucleotides and (12Ranganathan G. Vu D. Kern P.A. J. Biol. Chem. 1997; 272: 2515-2519Abstract Full Text Full Text PDF PubMed Scopus (35) Google Scholar). We cytoplasmic extracts from adipocytes from the and group of rats and added these extracts to an in vitro translation The cytoplasmic extract from the rats translation of LPL in the reticulocyte lysate However, when the transcript used in the at the extract translation, that the on the 3′-UTR involved in translation was To further identify the a gel shift analysis was using RNA corresponding to the 3′-UTR. These data indicated the presence of an RNA in the diabetic extract that with the RNA corresponding to nucleotides into the sequences of the other the for this RNA probably involves nucleotides The cytoplasmic extract from rats LPL but the gel shift reaction demonstrated for this is the of an RNA-binding protein or that involves The adipose tissue from rats RNA protein, which bind to the but be to the insulin Translational regulation of LPL has been identified previously the of from adipocytes G. R. Kern P.A. J. Biol. Chem. 1999; Full Text Full Text PDF PubMed Scopus Google and treatment of adipocytes with and thyroid hormone (11Kern P.A. Ranganathan G. Yukht A. Ong J.M. Davis R. J. Lipid Res. 1996; 37: 2332-2340Abstract Full Text PDF PubMed Google Scholar, J.M. Saffari B. R.B. Kern P.A. 1992; PubMed Scopus (35) Google Scholar). In the studies and thyroid were used to identify the RNA which was on the proximal 3′-UTR of LPL nucleotides and (12Ranganathan G. Vu D. Kern P.A. J. Biol. Chem. 1997; 272: 2515-2519Abstract Full Text Full Text PDF PubMed Scopus (35) Google Scholar). Thus, the RNA in the diabetic adipose tissue nucleotides and is different from that of treated and that translation inhibition from diabetes a different RNA-binding In insulin-deficient diabetic rats manifest low levels of adipose tissue LPL to an inhibition of LPL translation. This decrease in translation is to the interaction of a cytoplasmic with sequences on the 3′-UTR of the LPL mRNA. The further of this trans-acting be important in the of the associated with the diabetic We are to for and for with and