calpain regulatory [small] subunit-1 (CSS1, CDPS, CAPNS1, CAPN4, CAPNS)

Function

• regulatory subunit of Ca+2-regulated non-lysosomal thiol-protease which catalyzes limited proteolysis of substrates involved in cytoskeletal remodeling & signal transduction

Cofactor: Ca+2 (putative)

Structure

• homodimer or heterodimer of a large (catalytic) & a small (regulatory) subunit
• in presence of Ca+2, the heterodimer dissociates (putative)
• contact of the 5th EF-hand domain from each monomer allows formation of the homodimer & also appears to mediate contact between the large catalytic subunit & small regulatory subunit for the formation of the heterodimer
• contains 5 EF-hand domains
• EF-hand domains are paired
• EF-hand 1 is paired with EF-hand 2
• EF-hand 3 is paired with EF-hand 4
• EF-hand 5 domain, left unpaired, does not bind the Ca+2 but is responsible for dimerization by EF-embrace
• the 1st 4 EF-hand domains bind Ca+2

Compartment

• cytoplasm (putative)
• cell membrane
• translocates to the plasma membrane upon Ca+2 binding (putative

More general terms

• calpain regulatory [small] subunit (CANP small subunit)

Component of

• calpain

Database

• UniProt: http://www.uniprot.org/uniprot/P04632.html
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:826
• OMIM: https://mirror.omim.org/entry/114170
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=826