Ca+2-binding protein p22; calcineurin B homolog; calcineurin homologous protein; Ca+2-binding protein CHP (CHP)

Function

• required for constitutive membrane traffic
• inhibits GTPase-stimulated Na+/H+ exchange
• also inhibits calcineurin phosphatase activity
• required for activity of SLC9A1/NHE1
• both N-myristoylation & Ca+2-mediated conformational changes are essential for its function in exocytic traffic
• phosphorylated; decreased phosphorylation is associated with an increase in exchange activity
• phosphorylation state may regulate the binding to NHE1 monomer
• specifically binds to SLC9A1/NHE1 at a domain required for growth factor stimulation of exchange activity

Structure

contains 4 EF-hand domains

Compartment

cytoplasm (putative)

Expression

• ubiquitously expressed
• found in fetal eye, lung, liver, muscle, heart, kidney, thymus & spleen

More general terms

• Ca+2 binding protein
• myristoylated protein

Additional terms

• calcineurin-B or phosphatase-3 (2B) regulatory subunit

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=11261
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:11261
• OMIM: https://mirror.omim.org/entry/606988
• UniProt: http://www.uniprot.org/uniprot/Q99653.html