CCM3 signaling through sterile 20–like kinases plays an essential role during zebrafish cardiovascular development and cerebral cavernous malformations

Abstract

Cerebral cavernous malformation is a common human vascular disease that arises due to loss-of-function mutations in genes encoding

Structure-Function Analysis of Core STRIPAK Proteins

“…Interestingly, TORC2 controls actin cytoskeleton assembly across multiple species, in part via regulation of the Rho1 GTPases (43)(44)(45). CCM disease, CCM3, and MST4 are intimately linked to Rho signaling in human cells (12)(13)(14)46), suggesting that this function of STRIPAK has been evolutionarily conserved. In addition to these roles in cytoskeleton and membrane dynamics, a surprising recent report implicated the Drosophila STRIPAK complex (including CCM3) in Hippo signaling (47), indicating that STRIPAK may control multiple signaling pathways.…”

The Transcription Factor Atonal homolog 8 Regulates Gata4 and Friend of Gata-2 during Vertebrate Development

“…For the cardiac GFP studies, a previously described transgenic cardiac reporter zebrafish line was used (42,43). Morpholino oligonucleotides were obtained from Gene Tools and injected into one-cell stage embryos at the indicated doses.…”

“…Nuclear extracts were isolated from transfected cells as previously described (45). Immunoprecipitations were performed as previously described (42). FLAG-tagged Atoh8 was detected with HRP-conjugated anti-FLAG-M2 antibody (1:1000, Sigma).…”

Crystallization and preliminary crystallographic studies of CCM3 in complex with the C-terminal domain of MST4

“…Loss-of-function mutations cause an enlarged-heart phenotype in zebrafish (Zheng et al, 2010) and defects in early angiogenesis and early embryonic lethality in mouse . CCM3 has been identified to participate in vascular development by stabilizing vascular endothelial growth factor receptor 2 (VEGFR2) signalling and by mediating germinal centre kinase class III (GCKIII) kinase signalling (Zheng et al, 2010). It also can regulate neuronal survival and the activation of astrocytes (Louvi et al, 2011).…”

“…The interactions between CCM3 and GCKIII kinases play important roles in Golgi assembly, cell orientation and endothelial cell-cell junctions. They not only stabilize the activated GCKIII kinases, but also negatively regulate Rho by directly activating moesinen (Fidalgo et al, 2010;Zheng et al, 2010). Additionally, striatins and CCM3 can act as adapter molecules to bridge the GCKIIIs and a higher order complex termed STRIPAK (striatininteracting phosphatase and kinase; Goudreault et al, 2009).…”