Cotransin, a Sec61 translocation inhibitor, selectively prevents the stable insertion of certain nascent chains into the Sec61 translocation channel, exhibiting signal-sequence discrimination. This compound also inhibits the expression of VCAM-1 and p-selectin proteins by blocking their co-translational translocation across endoplasmic reticulum (ER) membranes (IC 50 =0.5-5 µM). Cotransin's role extends to potential applications in inflammation and immunity research [1] [2].

Cotransin inhibits the expression of proteins such as VCAM-1, P-selectin, angiotensinogen, β-lactamase, CRF1, ETBR, AQP2, HER-3, and TNF-α by preventing their cotranslational translocation across the endoplasmic reticulum (ER) membrane, with an IC50 range of 0.5-5 µM [1]. It also selectively inhibits a subset of secretory and membrane proteins [2]. In COS-7 cells, Cotransin at concentrations of 1 and 5 µM for 24 hours, exhibits selective, potent, and reversible inhibition of VCAM1 [2]. The compound interferes with signal sequence recognition by the Sec61 complex [2]. Western Blot Analysis [2] Cell Line: COS-7 cells (transfected with a VCAM1 expression plasmid or not) Concentration: 1, 5 µM Incubation Time: 24 h Result: Showed selective, potent and reversible inhibition to VCAM1.