Oxidative Stress Responsive 1 (OXSR1)

OSR1 belongs to the Ser/Thr protein kinase family of proteins. It regulates downstream kinases in response to environmental stress, and may play a role in regulating the actin cytoskeleton.

OXSR1 contains an N-terminal Ste20-like serine/threonine kinase domain and 2 C-terminal regions, designated PF1 and PF2, conserved with other members of the germinal center kinase (GCK) VI subfamily of Ste20 kinases, such as SPAK (STK39). At the end of the PF1 domain, OXSR1 has a putative caspase-3 (CASP3) cleavage site. Western blot analysis detected Oxsr1 at an apparent molecular mass of 58 kD in all mouse tissues examined except thymus. Cell fractionation and immunofluorescence analysis of HeLa cells showed that OXSR1 was distributed throughout the cell.