Catalog # AP4351

Arpc1b/p41-Arc (Thr-21), phospho-specific Antibody

Rabbit Polyclonal

Application / Dilution

Size 100 μl

Species Reactivity Hu, Rt, Ms, Ck, F

MW 41 kDa



Cellular morphology, adhesion, and motility occur through dynamic reorganization of actin-based superstructures. Actin-binding proteins are critical for regulating actin polymerization and superstructure formation. The Arp2/3 complex is an actin polymerization-inducing complex that includes Arp2, Arp3, p41-Arc, p34-Arc, p21-Arc, p20-Arc, and p16-Arc. Several nucleation promoting factors, such as WASP and coronin, regulate the activity of the Arp2/3 complex. In addition, the Arp2/3 complex may be regulated by phosphorylation of specific subunits in the complex. p41-Arc (Arpc1b) subunit Arpc1 has two isoforms in humans, Arpc1a and Arpc1b. PAK1 can bind and phosphorylate Thr-21 in Arpc1b leading to growth factor-stimulated cell motility. In addition, Arpc1b colocalizes with γ-tubulin at centrosomes and stimulates Aurora A activity. Aurora A phosphorylates Arpc1b on Thr-21 and a nonphosphorylatable Arpc1b mutant cannot activate Aurora A kinase and centrosome amplification. Thus, Arpc1b has roles in cytoskeletal dynamics during cell motility and mitosis, and these activities are regulated by phosphorylation at Thr-21.


Molli, P.R. et al. (2010) J Cell Biol. 190(1):101.
Vadlamudi, R.K. et al. (2004) EMBO Rep. 5(2):154.
Welch, M.D. et al. (1997) J Cell Biol. 138(2):375.

Western blot analysis of Arpc1b phosphorylation in human A431 stimulated with calyculin A (100 nM) for 30 min (lanes 1 & 3). The blots were treated with lambda phosphatase to remove phosphorylation (lanes 2 & 4), then probed with anti-Arpc1b (C-terminal region) (lanes 1 & 2) or anti-Arpc1b (Thr-21) (lanes 3 & 4).

Phospho-Arpc1b/p41-Arc (Thr-21) synthetic peptide (coupled to KLH) corresponding to amino acid residues surrounding threonine 21 in human Arpc1b. This peptide sequence is highly conserved in rat, mouse, chicken, and fish Arpc1b, and has some homology to the conserved site in isoform Arpc1a.

*For more information, see UniProt Accession O15143
Rabbit polyclonal, affinity-purified antibody is supplied in 100μl phosphate-buffered saline, 50% glycerol, 1 mg/ml BSA, and 0.05% sodium azide. Store at –20°C. Stable for 1 year.

The products are are safely shipped at ambient temperature for both domestic and international shipments. Each product is guaranteed to match the specifications as indicated on the corresponding technical data sheet. Please store at -20C upon arrival for long term storage.

This antibody was affinity purified using phospho-Arpc1b (Thr-21) peptide (without carrier). The antibody detects a 41 kDa* protein corresponding to the molecular mass of Arpc1b on SDS-PAGE immunoblots of human A431 and mouse C2C12 treated with calyculin A. This reactivity is removed with lambda phosphatase treatment.

*All molecular weights (MW) are confirmed by comparison to Bio-Rad Rainbow Markers and to western blot mobilities of known proteins with similar MW.

This kit contains: