Molecular cloning and expression of cDNA encoding a lumenal calcium binding glycoprotein from sarcoplasmic reticulum

Proc Natl Acad Sci U S A. 1989 Aug;86(16):6047-51. doi: 10.1073/pnas.86.16.6047.


Antibody screening was used to isolate a cDNA encoding the 160-kDa glycoprotein of rabbit skeletal muscle sarcoplasmic reticulum. The cDNA is identical to that encoding the 53-kDa glycoprotein except that it contains an in-frame insertion of 1308 nucleotides near its 5' end, apparently resulting from alternative splicing. The protein encoded by the cDNA would contain a 19-residue NH2-terminal signal sequence and a 453-residue COOH-terminal sequence identical to the 53-kDa glycoprotein. It would also contain a 436-amino acid insert between these sequences. This insert would be highly acidic, suggesting that it might bind Ca2+. The purified 160-kDa glycoprotein and the glycoprotein expressed in COS-1 cells transfected with cDNA encoding the 160-kDa glycoprotein were shown to bind 45Ca2+ in a gel overlay assay. The protein was shown to be located in the lumen of the sarcoplasmic reticulum and to be associated through Ca2+ with the membrane. We propose that this lumenal Ca2+ binding glycoprotein of the sarcoplasmic reticulum be designated "sarcalumenin."

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Blotting, Northern
  • Calcium-Binding Proteins / genetics*
  • Cloning, Molecular*
  • DNA / genetics*
  • Glycoproteins / genetics*
  • Molecular Sequence Data
  • Molecular Weight
  • Muscles / metabolism*
  • RNA, Messenger / genetics
  • RNA, Messenger / isolation & purification
  • Rabbits
  • Restriction Mapping
  • Sarcoplasmic Reticulum / metabolism*
  • Transcription, Genetic


  • Calcium-Binding Proteins
  • Glycoproteins
  • RNA, Messenger
  • DNA

Associated data

  • GENBANK/M25750