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Calcium‐dependent translocation of sorcin to membranes: functional relevance in contractile tissue
Author(s) -
Meyers Marian B.,
Zamparelli Carlotta,
Verzili Daniela,
Dicker Adam P.,
Blanck Thomas J.J.,
Chiancone Emilia
Publication year - 1995
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)01338-2
Subject(s) - chemistry , calcium , cytosol , chromosomal translocation , calcium binding protein , membrane , biophysics , microbiology and biotechnology , biochemistry , biology , enzyme , organic chemistry , gene
Sorcin, a 22 kDa calcium binding protein present in abundance in cardiac tissue and in multi‐drug resistant cells and previously described as a soluble protein, is now shown to undergo a calcium‐dependent translocation process from the cytosol to cellular membranes in both systems. The translocation process takes place also in E. coli BL21 cells that express recombinant sorcin, r‐sorcin, and can be exploited in the purification of the protein. Calcium binding to purified r‐sorcin occurs at micromolar concentrations of the metal and is accompanied by a conformational change that renders the protein soluble in the non‐ionic detergent Triton X‐114. This finding suggests that lipids are the target of sorcin on cellular membranes. The possible significance of the calcium‐dependent translocation of sorcin in the specialized functions of sorcin‐expressing cells is discussed.