title: Ubiquitylation of phosphatidylinositol 4-phosphate 5-kinase type I γ by HECTD1 regulates focal adhesion dynamics and cell migration.
abstract: Phosphatidylinositol 4-phosphate 5-kinase type I γ (PIPKIγ90) binds talin and localizes at focal adhesions (FAs). Phosphatidylinositol (4,5)-bisphosphate (PIP2) generated by PIPKIγ90 is essential for FA formation and cell migration. On the other hand, PIPKIγ90 and the β-integrin tail compete for overlapping binding sites on talin. Enhanced PIPKIγ90-talin interaction suppresses talin binding to the β-integrin. It is unknown how PIPKIγ90 is removed from the PIPKIγ90-talin complex after on-site PIP2 production during cell migration. Here we show that PIPKIγ90 is a substrate for HECTD1, an E3 ubiquitin ligase regulating cell migration. HECTD1 ubiquitinated PIPKIγ90 at lysine 97 and resulted in PIPKIγ90 degradation. Expression of the mutant PIPKIγ90(K97R) enhanced PIP2 and PIP3 production, inhibited FA assembly and disassembly and inhibited cancer cell migration, invasion and metastasis. Interestingly, mutation at tryptophan 647 abolished the inhibition of PIPKIγ90(K97R) on FA dynamics and partially rescued cancer cell migration and invasion. Thus, cycling PIPKIγ90 ubiquitylation by HECTD1 and consequent degradation remove PIPKIγ90 from talin after on-site PIP2 production, providing an essential regulatory mechanism for FA dynamics and cell migration.
authors.affiliation: Markey Cancer Center, University of Kentucky, Lexington, KY 40506, USA.
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhou
authors.forename: Manjula
authors.initials: M
authors.lastname: Sunkara
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Kutys
authors.forename: Zhaofei
authors.initials: Z
authors.lastname: Wu
authors.forename: Piotr
authors.initials: P
authors.lastname: Rychahou
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Morris
authors.forename: Haining
authors.initials: H
authors.lastname: Zhu
authors.forename: B Mark
authors.initials: BM
authors.lastname: Evers
authors.forename: Cai
authors.initials: C
authors.lastname: Huang
mesh_terms: D000818:Animals; D016466:CHO Cells; D002460:Cell Line; D002465:Cell Movement / Q000502:physiology*; D006224:Cricetinae; D003412:Cricetulus; D022001:Focal Adhesions / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D039641:Integrin beta Chains / Q000378:metabolism; D008239:Lysine / Q000378:metabolism; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D016608:Talin / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*; D054875:Ubiquitination / Q000502:physiology*
chemical_list: D039641:Integrin beta Chains; D019269:Phosphatidylinositol 4,5-Diphosphate; D016608:Talin; D044767:Ubiquitin-Protein Ligases; D017853:Phosphotransferases (Alcohol Group Acceptor); C020077:1-phosphatidylinositol-4-phosphate 5-kinase; D008239:Lysine
keywords: HECTD1; Invasion; Metastasis; PIP5K1C; Ubiquitylation