FHOD1 (Thr-1141), Phosphospecific Antibody

Formins include several families of proteins that regulate actin cytoskeletal dynamics via two conserved formin homology domains, FH1 and FH2. The FH1 region contains poly-proline stretches that promote interactions with profilin. The FH2 domain, located C-terminally to the FH1 domain, is highly conserved in formin proteins and possesses actin nucleation and polymerization activities. Through cooperation of FH1 and FH2, formins construct actin-based structures comprising linear, unbranched filaments that are used in stress fibers, actin cables, microspikes, and contractile rings. Several mammalian formins, including mDia1, FRL, and formin homology domain protein 1 (FHOD1) are inhibited through an intramolecular interaction between the C-terminal Dia autoregulatory domain (DAD) and its recognition region at the N-terminus. In FHOD1, this autoinhibitory interaction is disrupted through phosphorylation of Ser-1131, Ser-1137, and Thr-1141 by ROCK. Subsequent FHOD1 activation leads to stress fiber formation. In endothelial cells, thrombin activates this ROCK pathway, leading to FHOD1-mediated stress fiber formation.

This antibody was cross-adsorbed to unphosphorylated FHOD1 (Thr-1141) peptide before affinity purification using phospho-FHOD1 (Thr-1141) peptide (without carrier) . The antibody detects a 140 kDa* protein corresponding to the apparent molecular mass of FHOD1 on SDS-PAGE immunoblots of human K562 and mouse C2C12 cells treated with calyculin A. This peptide sequence is highly conserved in rat and mouse FHOD1, and is well conserved in FHOD3 (Thr-1399) .