Anti-Phospho-MBS (MYPT1) (Thr696) mAb

WB - 1-2 ug/mL ELISA - 1 ug/mL

The expression of a constitutively active form of Rho-kinase induced stress fiber and focal adhesion formation in fibroblasts and an increase in the level of myosin light chain (MLC20) phosphorylation (1). These results in smooth muscle and in non-muscle cells are attributed to an increase in MLC20 phosphorylation and this is thought to reflect the inhibition of myosin phosphatase (MP). MP is composed of three subunits: a catalytic subunit of type 1 phosphatase delta isoform, PP1c delta, and two non-catalytic subunits, 110 and 20 kDa. The 110-kDa subunit is a targeting molecule and thus has been termed myosin phosphatase target subunit 1 (MYPT1) or myosin-binding subunit (MBS). MYPT1/ MBS is the key molecule involved in regulation of MP activity (2). Phosphorylation by Rho-kinase inhibited MP activity and this reflected a decrease in Vmax. Activity of MP with different substrates also was inhibited by phosphorylation. Two major sites of phosphorylation on chicken MYPT1/ MBS were Thr695 and Thr850. Various point mutations were designed for these phosphorylation sites. Following this phosphorylation by Rho-kinase and assays of phosphatase activity it was determined that Thr695 was responsible for inhibition. Rho-kinase, which is activated by GTP-RhoA, phosphorylated MYPT1/ MBS and consequently inactivated myosin phosphatase (MP). Over-expression of RhoA or activated RhoA in NIH 3T3 cells increased phosphorylation of MYPT1/ MBS and MLC20. Thus, Rho appears to inhibit myosin phosphatase through the action of Rho-kinase.

1.0 mg/mL

Supplied in 20mM phosphatase buffer (pH 7.5), 300mM NaCl, 50% glycerol.

Human: 4659 Mouse: 17931

Synthetic peptide-KLH phosphorylation of Thr696 of human near MBS/MYPT1

Phospho-MBS/MYPT1 Thr696 Antibody detects endogenous MBS/ MYPT1 only when phosphorylated at threonine696. The antibody does not recognize other myosin phosphatase regulatory subunits. The antibody detects the ~115 kDa MBS protein by Western blotting analysis.

1 year

This monoclonal antibody (clone AF20) was produced by immunizing mice with a synthetic phosphopeptide (coupled to KLH) corresponding to amino acid residues surrounding Thr696 of human MBS/ MYPT1. The IgG fraction was purified by protein A-Sepharose chromatography.

MBS/MYPT1