Rho Inhibitor II, Y16

A cell-permeable pyrazolidinedione compound that prevents RhoGEFs LARG, p115, and PDZ from interacting with RhoA, while displaying little potency against DBL-RhoA, LBC-RhoA, intersectin-Cdc42, or TrioN-Cdc42 interaction. Structure and in vitro binding studies using DH-PH domains-containing human LARG catalytic fragment (aa 765-1138) constructs reveals RhoGEF DH-PH domain junction as the high affinity Y16 targeting site (K_d = 65, 472, 2121, and >5 x 10⁵ nM using wt, K979A, E982A, and N983A LARG, respectively). Shown to prevent serum-induced activation of cellular RhoA, but not Cdc42 or Rac1, in serum-starved NIH-3T3 cultures (215%, 109%, and 87% of basal RhoA-GTP level with 0, 10, or 30 µM Y16, respectively) and effectively inhibit RhoA downstream signaling events, including FAK and MLC phosphorylations and stress fiber formation without apparent cytotoxicity (50 µM up to 24 h) or affecting Cdc42-mediated filapodia and Rac1-mediated lamellipodia formation. Greatly synergizes with Rho GEF-binding domain blocker Rhosin (Cat. No. 555460) in blocking RhoA-LARG binding (8%, 27%, and 72% inhibition, respectively, with 5 µM G04 alone, 5 µM Y16 alone, or in combination) and in inhibiting cellular RhoA activation (80% inhibition of serum-stimulated RhoA-GTP level by 30 µM Y16 alone or by a combination of 5 µM each of G04 and Y16 in serum-starved NIH-3T3 cells).

Cell permeable: yes

Primary Target
RhoGEF

Reversible: yes

Packaged under inert gas

Following reconstitution, aliquot and freeze -20°C. Stock solutions are stable for up to 3 months at -20°C.

Shang, X., et al. 2013. Proc. Natl. Acad. Sci. USA.110, 3155.

CALBIOCHEM is a registered trademark of Merck KGaA, Darmstadt, Germany

Toxicity: Standard Handling (A)