SARAF
Domain
The cytoplasmic C-terminal region mediates interaction with STIM1, while the N-terminal lumenal region mediates regulation of SOCE activity.
Function
Negative regulator of store-operated Ca(2+) entry (SOCE) involved in protecting cells from Ca(2+) overfilling. In response to cytosolic Ca(2+) elevation after endoplasmic reticulum Ca(2+) refilling, promotes a slow inactivation of STIM (STIM1 or STIM2)-dependent SOCE activity: possibly act by facilitating the deoligomerization of STIM to efficiently turn off ORAI when the endoplasmic reticulum lumen is filled with the appropriate Ca(2+) levels, and thus preventing the overload of the cell with excessive Ca(2+) ions.
Sequence Similarities
Belongs to the SARAF family.
Tissue Specificity
Highly expressed in macrophages.
Cellular localization
- Endoplasmic reticulum membrane
- Single-pass type I membrane protein
- Translocates to the endoplasmic reticulum-plasma membrane (ER-PM) region in a STIM1-dependent manner following cytosolic Ca(2+) elevation.
- Isoform 2
- Endoplasmic reticulum membrane
- Single-pass type I membrane protein
Alternative names
TMEM66, XTP3, HSPC035, NPD003, PSEC0019, UNQ1967/PRO4499, SARAF, Store-operated calcium entry-associated regulatory factor, SOCE-associated regulatory factor, HBV X-transactivated gene 3 protein, HBV XAg-transactivated protein 3, Protein FOAP-7, Transmembrane protein 66