Key Points
- To identify and characterize cDNAs encoding calcium-transporting ATPases and related cation pumps expressed across diverse rat nonmuscle tissues.
- Screened rat brain, kidney, and stomach cDNA libraries using a synthetic oligonucleotide hybridization probe derived from a 23-amino acid ATP-binding site motif of sarcoplasmic reticulum Ca-ATPase.
- Isolated, cloned, and sequenced reactive cDNA transcripts to determine their full-length nucleotide sequences and predicted amino acid structures.
- Identified cDNAs for the plasma membrane Ca-ATPase, Na+,K+-ATPase, gastric H+,K+-ATPase, an uncharacterized transport ATPase, and two slow-twitch muscle sarcoplasmic reticulum Ca-ATPase gene products.
- Identified an alternatively spliced transcript present in brain, kidney, and stomach that encodes a 1043-amino acid Ca-ATPase isoform, contrasting with the 997-amino acid slow-twitch muscle isoform.
- Demonstrated that the nonmuscle isoform substitutes the muscle C-terminal tetrapeptide with a 50-amino acid sequence containing a putative transmembrane domain and a consensus N-linked glycosylation site.
Structured PICO
PPopulationRat brain, kidney, and stomach cDNA libraries
IInterventionScreening with an oligonucleotide hybridization probe corresponding to a 23-amino acid sequence from part of the ATP-binding site of the sarcoplasmic reticulum Ca-ATPase
OOutcomeIdentification and sequencing of cDNAs encoding Ca2+-transporting ATPases and other cation-transporting ATPases
Identified a novel alternatively spliced transcript of the slow-twitch muscle sarcoplasmic reticulum Ca-ATPase gene expressed in rat brain, kidney, and stomach.