Crystal Structure of ROCK 1 bound to fasudil
[ROCK1_HUMAN] Protein kinase which is a key regulator of actin cytoskeleton and cell polarity. Involved in regulation of smooth muscle contraction, actin cytoskeleton organization, stress fiber and focal adhesion formation, neurite retraction, cell adhesion and motility via phosphorylation of DAPK3, GFAP, LIMK1, LIMK2, MYL9/MLC2, PFN1 and PPP1R12A. Phosphorylates FHOD1 and acts synergistically with it to promote SRC-dependent non-apoptotic plasma membrane blebbing. Phosphorylates JIP3 and regulates the recruitment of JNK to JIP3 upon UVB-induced stress. Acts as a suppressor of inflammatory cell migration by regulating PTEN phosphorylation and stability. Acts as a negative regulator of VEGF-induced angiogenic endothelial cell activation. Required for centrosome positioning and centrosome-dependent exit from mitosis. Plays a role in terminal erythroid differentiation. May regulate closure of the eyelids and ventral body wall by inducing the assembly of actomyosin bundles. Promotes keratinocyte terminal differentiation.             
Publication Abstract from PubMed
ROCK or Rho-associated kinase, a serine/threonine kinase, is an effector of Rho-dependent signaling and is involved in actin-cytoskeleton assembly and cell motility and contraction. The ROCK protein consists of several domains: an N-terminal region, a kinase catalytic domain, a coiled-coil domain containing a RhoA binding site, and a pleckstrin homology domain. The C-terminal region of ROCK binds to and inhibits the kinase catalytic domains, and this inhibition is reversed by binding RhoA, a small GTPase. Here we present the structure of the N-terminal region and the kinase domain. In our structure, two N-terminal regions interact to form a dimerization domain linking two kinase domains together. This spatial arrangement presents the kinase active sites and regulatory sequences on a common face affording the possibility of both kinases simultaneously interacting with a dimeric inhibitory domain or with a dimeric substrate. The kinase domain adopts a catalytically competent conformation; however, no phosphorylation of active site residues is observed in the structure. We also determined the structures of ROCK bound to four different ATP-competitive small molecule inhibitors (Y-27632, fasudil, hydroxyfasudil, and H-1152P). Each of these compounds binds with reduced affinity to cAMP-dependent kinase (PKA), a highly homologous kinase. Subtle differences exist between the ROCK- and PKA-bound conformations of the inhibitors that suggest that interactions with a single amino acid of the active site (Ala215 in ROCK and Thr183 in PKA) determine the relative selectivity of these compounds. Hydroxyfasudil, a metabolite of fasudil, may be selective for ROCK over PKA through a reversed binding orientation.
The structure of dimeric ROCK I reveals the mechanism for ligand selectivity.,Jacobs M, Hayakawa K, Swenson L, Bellon S, Fleming M, Taslimi P, Doran J J Biol Chem. 2006 Jan 6;281(1):260-8. Epub 2005 Oct 24. PMID:16249185
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.