SBF2
Description
The SBF2 (SET binding factor 2) is a protein-coding gene located on chromosome 11.
SBF2, also known as Myotubularin-related protein 13, is a protein encoded by the SBF2 gene in humans. SBF2 belongs to the family of myotubularin-related proteins, which includes lipid phosphatases like MTM1 and pseudophosphatases like SBF1. Pseudophosphatases contain inactivating substitutions at the catalytic cysteine.
SBF2 acts as a guanine nucleotide exchange factor (GEF) that activates RAB21 and possibly RAB28, promoting the exchange of GDP to GTP and converting inactive GDP-bound Rab proteins into their active GTP-bound form. In response to starvation-induced autophagy, SBF2 activates RAB21, which then binds to and regulates SNARE protein VAMP8 endolysosomal transport necessary for SNARE-mediated autophagosome-lysosome fusion. SBF2 also functions as an adapter for the phosphatase MTMR2, enhancing its catalytic activity towards phosphatidylinositol 3,5-bisphosphate and, to a lesser extent, phosphatidylinositol 3-phosphate.
SBF2 is also known as CMT4B2, DENND7B, MTMR13.
