Molecular mechanism for the regulation of rho-kinase by dimerization and its inhibition by fasudil.
Rho-kinase is a key regulator of cytoskeletal events and a promising drug target in the treatment of vascular diseases and neurological disorders. Unlike other protein kinases, Rho-kinase requires both N- and C-terminal extension segments outside the kinase domain for activity, although the details of this requirement have been elusive. The crystal structure of an active Rho-kinase fragment containing the kinase domain and both the extensions revealed a head-to-head homodimer through the N-terminal extension forming a helix bundle that structurally integrates the C-terminal extension. This structural organization enables binding of the C-terminal hydrophobic motif to the N-terminal lobe, which defines the correct disposition of helix alphaC that is important for the catalytic activity. The bound inhibitor fasudil significantly alters the conformation and, consequently, the mode of interaction with the catalytic cleft that contains local structural changes. Thus, both kinase and drug conformational pliability and stability confer selectivity.
Structural Biology Laboratory, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
Hiroto
H
Yamaguchi
Miyuki
M
Kasa
Mutsuki
M
Amano
Kozo
K
Kaibuchi
Toshio
T
Hakoshima
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D000595:Amino Acid Sequence; D002384:Catalysis; D020134:Catalytic Domain; D017868:Cyclic AMP-Dependent Protein Kinases; D019281:Dimerization; D057927:Hydrophobic and Hydrophilic Interactions; D047908:Intracellular Signaling Peptides and Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010770:Phosphotransferases / Q000737:chemistry* / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D054460:rho-Associated Kinases
D047908:Intracellular Signaling Peptides and Proteins; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D010770:Phosphotransferases; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; C049347:fasudil