title: NHERF1 regulates actin cytoskeleton organization through modulation of α-actinin-4 stability.
abstract: The actin cytoskeleton is composed of a highly dynamic network of filamentous proteins, yet the molecular mechanism that regulates its organization and remodeling remains elusive. In this study, Na(+)/H(+) exchanger regulatory factor (NHERF)-1 loss-of-function and gain-of-function experiments reveal that polymerized actin cytoskeleton (F-actin) in HeLa cells is disorganized by NHERF1, whereas actin protein expression levels exhibit no detectable change. To elucidate the molecular mechanism underlying actin cytoskeleton disorganization by NHERF1, a combined 2-dimensional electrophoresis-matrix-assisted laser desorption/ionization-time of flight mass spectrometry approach was used to screen for proteins regulated by NHERF1 in HeLa cells. α-Actinin-4, an actin cross-linking protein, was identified. Glutathione S-transferase pull-down and coimmunoprecipitation studies showed the α-actinin-4 carboxyl-terminal region specifically interacted with the NHERF1 postsynaptic density 95/disc-large/zona occludens-1 domain. The NHERF1/α-actinin-4 interaction increased α-actinin-4 ubiquitination and decreased its expression levels, resulting in actin cytoskeleton disassembly. Our study identified α-actinin-4 as a novel NHERF1 interaction partner and provided new insights into the regulatory mechanism of the actin cytoskeleton by NHERF1.
authors.affiliation: *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom.
authors.forename: Licui
authors.initials: L
authors.lastname: Sun
authors.affiliation: *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom.
authors.forename: Junfang
authors.initials: J
authors.lastname: Zheng
authors.affiliation: *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom.
authors.forename: Qiqi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom.
authors.forename: Ran
authors.initials: R
authors.lastname: Song
authors.affiliation: *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom.
authors.forename: Hua
authors.initials: H
authors.lastname: Liu
authors.affiliation: *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom.
authors.forename: Ran
authors.initials: R
authors.lastname: Meng
authors.affiliation: *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom.
authors.forename: Tao
authors.initials: T
authors.lastname: Tao
authors.affiliation: *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom.
authors.forename: Yang
authors.initials: Y
authors.lastname: Si
authors.affiliation: *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom.
authors.forename: Wenguo
authors.initials: W
authors.lastname: Jiang
authors.affiliation: *Department of Biochemistry and Molecular Biology, Capital Medical University, Beijing, China; Beijing Key Laboratory for Tumor Invasion and Metastasis, Capital Medical University-Cardiff University Joint Centre for Biomedical Research, Cancer Institute of Capital Medical University, Beijing, China; and Metastasis and Angiogenesis Research Group, Department of Surgery, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom jq_he@ccmu.edu.cn.
authors.forename: Junqi
authors.initials: J
authors.lastname: He
mesh_terms: D000185:Actinin / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D003599:Cytoskeleton / Q000502:physiology*; D015536:Down-Regulation; D005786:Gene Expression Regulation / Q000502:physiology; D055785:Gene Knockdown Techniques; D006367:HeLa Cells; D006801:Humans; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000378:metabolism*; D025801:Ubiquitin / Q000378:metabolism
chemical_list: C111453:ACTN4 protein, human; D010750:Phosphoproteins; D017923:Sodium-Hydrogen Exchangers; D025801:Ubiquitin; C093376:sodium-hydrogen exchanger regulatory factor; D000185:Actinin; D046988:Proteasome Endopeptidase Complex
keywords: F-actin; PDZ; protein interaction; stress fiber; ubiquitination