stromal interaction molecule 1 (STIM1, GOK)

Function

• role in mediating Ca+2 influx following depletion of intracellular Ca+2 stores
• acts as Ca+2 sensor in the endoplasmic reticulum (ER) via its EF-hand domain
• upon Ca+2 depletion, translocates from the ER to the plasma membrane where it activates the Ca+2 release-activated Ca+2 (CRAC) channel subunit, TMEM142A/ORAI1.
• forms homooligomers & heteroligomers with STIM2

Structure

• glycosylation is required for cell surface expression.
• phosphorylated predominantly on Ser
• contains 1 EF-hand domain
  • contains 1 SAM domain (sterile alpha motif)

Compartment

• cell membrane, endoplasmic reticulum membrane
• translocates from the endoplasmic reticulum to the plasma membrane in response to depletion of intracellular Ca+2

Expression

ubiquitously expressed

Pathology

• defects in STIM1 may cause rhabdomyosarcoma & rhabdoid tumors

More general terms

• Ca+2 binding protein
• glycoprotein
• membrane protein

Database

• OMIM: https://mirror.omim.org/entry/605921
• UniProt: http://www.uniprot.org/uniprot/Q13586.html