Calcium binding proteins in the sarcoplasmic/endoplasmic reticulum of muscle and nonmuscle cells.
In this paper we review some of the large quantities of information currently available concerning the identification, structure and function of Ca(2+)-binding proteins of endoplasmic and sarcoplasmic reticulum membranes. The review places particular emphasis on identification and discussion of Ca2+ 'storage' proteins in these membranes. We believe that the evidence reviewed here supports the contention that the Ca(2+)-binding capacity of both calsequestrin and calreticulin favor their contribution as the major Ca(2+)-binding proteins of muscle and nonmuscle cells, respectively. Other Ca(2+)-binding proteins discovered in both endoplasmic reticulum and sarcoplasmic reticulum membranes probably contribute to the overall Ca2+ storage capacity of these membrane organelles, and they also play other important functional role such as posttranslational modification of newly synthesized proteins, a cytoskeletal (structural) function, or movement of Ca2+ within the lumen of the sarcoplasmic/endoplasmic reticulum towards the storage sites.
Milner
R E
RE
Department of Biochemistry, University of Alberta, Edmonton, Canada.
Famulski
K S
KS
Michalak
M
M
D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000737:chemistry*; D006801:Humans; D009132:Muscles / Q000737:chemistry*; D012519:Sarcoplasmic Reticulum / Q000737:chemistry; D014018:Tissue Distribution
D002135:Calcium-Binding Proteins; D002118:Calcium