SRMS/SRM

SRMS (Src-related kinase lacking C-terminal regulatory tyrosine and N-terminal myristoylation site, also called SRM) is an atypical Src-family member whose unwieldy name records its two structural anomalies: it lacks both the N-terminal myristoylation signal that anchors Src kinases at membranes and the C-terminal regulatory tyrosine phosphorylated by CSK. Free of these constraints, SRMS localizes to the cytoplasm and nucleus rather than the plasma membrane and may evade classical Src-family autoinhibition. SRMS is expressed during embryogenesis and in adult tissues. Reported substrates, including the RNA-binding protein Sam68, hint at roles in RNA processing, migration and proliferation, but SRMS remains one of the least characterized human tyrosine kinases, without drugs or firm disease associations.