SRP54

Cat. No.	Available in
18400	0.1 mg
18401	1 mg

Data Sheet

Specification Sheet

MSDS

SRP54 is a 54-kDa subunit of the signal recognition particle (SRP), a cytoplasmic ribonucleoprotein complex that directs the translocation of newly synthesized secretory proteins from the polysome to the endoplasmic reticulum. SRP is composed of six polypeptides and a tRNA-like molecule known as 7SL RNA. The SRP54 subunit is a GTP-binding protein and directly binds the signal sequences of nascent secretory and membrane proteins.

Anti-SRP autoantibodies occur in patients with polymyositis, an autoimmune chronic muscle inflammation. These auto-antibodies predominantly recognize the SRP54 subunit and can also immunoprecipitate several of the SRP subunits and the RNA component. About 5% of myositis patients are positive for anti-SRP autoantibodies, rising to 18% in the subgroup of Jo-1 autoantibody-negative patients. The classic 'anti-SRP syndrome' is a severe form of polymyositis in which the myositic inflammation is acute and aggressive in onset, with common myalgias and cardiac involvement. A poor response to therapy is normally observed, with a 5-year survival rate in the range of 25%.

DIARECT produces full-length recombinant human SRP54 in the baculovirus/Sf9 expression system.