SRP54
| Cat. No. | Available in | ![]() |
| 18400 | 0.1 mg | |
| 18401 | 1 mg | |
Diseases:
Polymyositis and Dermatomyositis
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.


