| Structural highlights
Disease
KRIT1_HUMAN Hereditary cerebral cavernous malformation. Cerebral cavernous malformations 1 (CCM1) [MIM:116860: A congenital vascular anomaly of the central nervous system that can result in hemorrhagic stroke, seizures, recurrent headaches, and focal neurologic deficits. The lesions are characterized by grossly enlarged blood vessels consisting of a single layer of endothelium and without any intervening neural tissue, ranging in diameter from a few millimeters to several centimeters. Note=The disease is caused by mutations affecting the gene represented in this entry.[1]
Function
KRIT1_HUMAN Component of the CCM signaling pathway which is a crucial regulator of heart and vessel formation and integrity (By similarity). Negative regulator of angiogenesis. Inhibits endothelial proliferation, apoptosis, migration, lumen formation and sprouting angiogenesis in primary endothelial cells. Promotes AKT phosphorylation in a NOTCH-dependent and independent manner, and inhibits EKR1/2 phosphorylation indirectly through activation of the DELTA-NOTCH cascade. Acts in concert with CDH5 to establish and maintain correct endothelial cell polarity and vascular lumen and these effects are mediated by recruitment and activation of the Par polarity complex and RAP1B. Required for the localization of phosphorylated PRKCZ, PARD3, TIAM1 and RAP1B to the cell junction, and cell junction stabilization. Plays a role in integrin signaling via its interaction with ITGB1BP1; this prevents the interaction between ITGB1 and ITGB1BP1. Plays an important role in the maintenance of the intracellular reactive oxygen species (ROS) homeostasis to prevent oxidative cellular damage. Regulates the homeostasis of intracellular ROS through an antioxidant pathway involving FOXO1 and SOD2. Facilitates the down-regulation of cyclin-D1 (CCND1) levels required for cell transition from proliferative growth to quiescence by preventing the accumulation of intracellular ROS through the modulation of FOXO1 and SOD2 levels.[2] [3] [4] [5] [REFERENCE:17]
Publication Abstract from PubMed
Cerebral cavernous malformations (CCM) are vascular dysplasias that usually occur in the brain and are associated with mutations in the KRIT1/CCM1, CCM2/MGC4607/OSM/Malcavernin, and PDCD10/CCM3/TFAR15 genes. Here we report the 2.9A crystal structure of the ankyrin repeat domain (ARD) and FERM domain of the protein product of KRIT1 (KRIT1; Krev interaction trapped 1). The crystal structure reveals that the KRIT1 ARD contains 4 ankyrin repeats. There is an unusual conformation in the ANK4 repeat that is stabilized by Trp-404, and the structure reveals a solvent exposed ankyrin groove. Domain orientations of the three copies within the asymmetric unit suggest a stable interaction between KRIT1 ARD and FERM domains, indicating a globular ARD-FERM module. This resembles the additional F0 domain found N-terminal to the FERM domain of talin. Structural analysis of KRIT1 ARD-FERM highlights surface regions of high evolutionary conservation, and suggests potential sites that could mediate interaction with binding partners. The structure therefore provides a better understanding of KRIT1 at the molecular level.
Structural analysis of the KRIT1 ankyrin repeat and FERM domains reveals a conformationally stable ARD-FERM interface.,Zhang R, Li X, Boggon TJ J Struct Biol. 2015 Dec;192(3):449-56. doi: 10.1016/j.jsb.2015.10.006. Epub 2015 , Oct 14. PMID:26458359[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Kehrer-Sawatzki H, Wilda M, Braun VM, Richter HP, Hameister H. Mutation and expression analysis of the KRIT1 gene associated with cerebral cavernous malformations (CCM1). Acta Neuropathol. 2002 Sep;104(3):231-40. Epub 2002 Jun 26. PMID:12172908 doi:10.1007/s00401-002-0552-6
- ↑ Lampugnani MG, Orsenigo F, Rudini N, Maddaluno L, Boulday G, Chapon F, Dejana E. CCM1 regulates vascular-lumen organization by inducing endothelial polarity. J Cell Sci. 2010 Apr 1;123(Pt 7):1073-80. doi: 10.1242/jcs.059329. PMID:20332120 doi:10.1242/jcs.059329
- ↑ Goitre L, Balzac F, Degani S, Degan P, Marchi S, Pinton P, Retta SF. KRIT1 regulates the homeostasis of intracellular reactive oxygen species. PLoS One. 2010 Jul 26;5(7):e11786. doi: 10.1371/journal.pone.0011786. PMID:20668652 doi:10.1371/journal.pone.0011786
- ↑ Wustehube J, Bartol A, Liebler SS, Brutsch R, Zhu Y, Felbor U, Sure U, Augustin HG, Fischer A. Cerebral cavernous malformation protein CCM1 inhibits sprouting angiogenesis by activating DELTA-NOTCH signaling. Proc Natl Acad Sci U S A. 2010 Jul 13;107(28):12640-5. doi:, 10.1073/pnas.1000132107. Epub 2010 Jun 24. PMID:20616044 doi:10.1073/pnas.1000132107
- ↑ Liu JJ, Stockton RA, Gingras AR, Ablooglu AJ, Han J, Bobkov AA, Ginsberg MH. A mechanism of Rap1-induced stabilization of endothelial cell--cell junctions. Mol Biol Cell. 2011 Jul 15;22(14):2509-19. doi: 10.1091/mbc.E11-02-0157. Epub, 2011 Jun 1. PMID:21633110 doi:10.1091/mbc.E11-02-0157
- ↑ Zhang R, Li X, Boggon TJ. Structural analysis of the KRIT1 ankyrin repeat and FERM domains reveals a conformationally stable ARD-FERM interface. J Struct Biol. 2015 Dec;192(3):449-56. doi: 10.1016/j.jsb.2015.10.006. Epub 2015 , Oct 14. PMID:26458359 doi:http://dx.doi.org/10.1016/j.jsb.2015.10.006
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