2rmk

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Rac1/PRK1 Complex

spinqualitylabelsall models 2rmk, 25 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2rmk is a 2 chain structure with sequence from Human. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: GCP, MG Gene: RAC1 (HUMAN), PKN1, PKN, PRK1, PRKCL1 (HUMAN) Activity: Protein kinase C, with EC number 2.7.11.13 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Warning: this is a large structure, and loading might take a long time or not happen at all. Function [RAC1_HUMAN] Plasma membrane-associated small GTPase which cycles between active GTP-bound and inactive GDP-bound states. In its active state, binds to a variety of effector proteins to regulate cellular responses such as secretory processes, phagocytosis of apoptotic cells, epithelial cell polarization and growth-factor induced formation of membrane ruffles. Rac1 p21/rho GDI heterodimer is the active component of the cytosolic factor sigma 1, which is involved in stimulation of the NADPH oxidase activity in macrophages (By similarity). Essential for the SPATA13-mediated regulation of cell migration and adhesion assembly and disassembly. Stimulates PKN2 kinase activity. In concert with RAB7A, plays a role in regulating the formation of RBs (ruffled borders) in osteoclasts. In glioma cells, promotes cell migration and invasion. Isoform B has an accelerated GEF-independent GDP/GTP exchange and an impaired GTP hydrolysis, which is restored partially by GTPase-activating proteins. It is able to bind to the GTPase-binding domain of PAK but not full-length PAK in a GTP-dependent manner, suggesting that the insertion does not completely abolish effector interaction. [PKN1_HUMAN] PKC-related serine/threonine-protein kinase involved in various processes such as regulation of the intermediate filaments of the actin cytoskeleton, cell migration, tumor cell invasion and transcription regulation. Regulates the cytoskeletal network by phosphorylating proteins such as VIM and neurofilament proteins NEFH, NEFL and NEFM, leading to inhibit their polymerization. Phosphorylates 'Ser-575', 'Ser-637' and 'Ser-669' of MAPT/Tau, lowering its ability to bind to microtubules, resulting in disruption of tubulin assembly. Acts as a key coactivator of androgen receptor (ANDR)-dependent transcription, by being recruited to ANDR target genes and specifically mediating phosphorylation of 'Thr-11' of histone H3 (H3T11ph), a specific tag for epigenetic transcriptional activation that promotes demethylation of histone H3 'Lys-9' (H3K9me) by KDM4C/JMJD2C. Phosphorylates HDAC5, HDAC7 and HDAC9, leading to impair their import in the nucleus. Phosphorylates 'Thr-38' of PPP1R14A, 'Ser-159', 'Ser-163' and 'Ser-170' of MARCKS, and GFAP. Able to phosphorylate RPS6 in vitro. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Protein kinase C-related kinase 1 (PRK1 or PKN) is involved in regulation of the intermediate filaments of the actin cytoskeleton, as well as having effects on processes as diverse as mitotic timing and apoptosis. It is activated by interacting with the Rho family small G proteins and arachidonic acid or by caspase cleavage. We have previously shown that the HR1b of PRK1 binds exclusively to Rac1, whereas the HR1a domain binds to both Rac1 and RhoA. Here, we have determined the solution structure of the HR1b-Rac complex. We show that HR1b binds to the C-terminal end of the effector loop and switch 2 of Rac1. Comparison with the HR1a-RhoA structure shows that this part of the Rac1-HR1b interaction is homologous to one of the contact sites that HR1a makes with RhoA. The Rac1 used in this study included the C-terminal polybasic region, which is frequently omitted from structural studies, as well as the core G domain. The Rac1 C-terminal region reverses in direction to interact with residues in switch 2, and the polybasic region itself interacts with residues in HR1b. The interactions with HR1b do not prevent the polybasic region being available to contact the negatively charged membrane phospholipids, which is considered to be its primary role. This is the first structural demonstration that the C terminus of a G protein forms a novel recognition element for effector binding. The Rac1 polybasic region is required for interaction with its effector PRK1.,Modha R, Campbell LJ, Nietlispach D, Buhecha HR, Owen D, Mott HR J Biol Chem. 2008 Jan 18;283(3):1492-500. Epub 2007 Nov 15. PMID:18006505 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Rac Serine/threonine protein kinase

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