title: Deacetylation of HSPA5 by HDAC6 leads to GP78-mediated HSPA5 ubiquitination at K447 and suppresses metastasis of breast cancer.
abstract: Heat-shock protein 5 (HSPA5) is a marker for poor prognosis in breast cancer patients and has an important role in cancer progression, including promoting drug resistance and metastasis. In this study, we identify that the specific lysine residue 447 (K447) of HSPA5 could be modified with polyubiquitin for subsequent degradation through the ubiquitin proteasomal system, leading to the suppression of cell migration and invasion of breast cancer. We further found that GP78, an E3 ubiquitin ligase, interacted with the C-terminal region of HSPA5 and mediated HSPA5 ubiquitination and degradation. Knock down of GP78 significantly increased the expression of HSPA5 and enhanced migration/invasive ability of breast cancer cells. Knock down of histone deacetylase-6 (HDAC6) increased the acetylation of HSPA5 at lysine residues 353 (K353) and reduced GP78-mediated ubiquitination of HSPA5 at K447 and then increased cell migration/invasion. In addition, we demonstrate that E3 ubiquitin ligase GP78 preferentially binds to deacetylated HSPA5. Notably, the expression levels of GP78 inversely correlated with HSPA5 levels in breast cancer patients. Patients with low GP78 expression significantly correlated with invasiveness of breast cancer, advanced tumor stages and poor clinical outcome. Taken together, our results provide new mechanistic insights into the understanding that deacetylation of HSPA5 by HDAC6 facilitates GP78-mediated HSPA5 ubiquitination and suggest that post-translational regulation of HSPA5 protein is critical for HSPA5-mediated metastatic properties of breast cancer.
authors.affiliation: National Institute of Cancer Research, National Health Research Institutes, Zhunan, Taiwan.
authors.forename: Y-W
authors.initials: YW
authors.lastname: Chang
authors.affiliation: National Institute of Cancer Research, National Health Research Institutes, Zhunan, Taiwan.|Graduate Program of Biotechnology in Medicine College of Life Science, National Tsing Hua University, Hsinchu, Taiwan.
authors.forename: C-F
authors.initials: CF
authors.lastname: Tseng
authors.affiliation: Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: M-Y
authors.initials: MY
authors.lastname: Wang
authors.affiliation: Graduate Institute of Cancer Biology, China Medical University, Taichung, Taiwan.
authors.forename: W-C
authors.initials: WC
authors.lastname: Chang
authors.affiliation: Core Facilities for Protein Structural Analysis, Academia Sinica, Taipei, Taiwan.
authors.forename: C-C
authors.initials: CC
authors.lastname: Lee
authors.affiliation: National Institute of Cancer Research, National Health Research Institutes, Zhunan, Taiwan.
authors.forename: L-T
authors.initials: LT
authors.lastname: Chen
authors.affiliation: Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: M-C
authors.initials: MC
authors.lastname: Hung
authors.affiliation: National Institute of Cancer Research, National Health Research Institutes, Zhunan, Taiwan.|Graduate Institute of Cancer Biology, China Medical University, Taichung, Taiwan.|Center for Molecular Medicine, China Medical University Hospital, Taichung, Taiwan.|Department of Biotechnology, Asia University, Taichung, Taiwan.
authors.forename: J-L
authors.initials: JL
authors.lastname: Su
mesh_terms: D000107:Acetylation; D000595:Amino Acid Sequence; D000818:Animals; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D000091342:Endoplasmic Reticulum Chaperone BiP; D005260:Female; D055785:Gene Knockdown Techniques; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000073864:Histone Deacetylase 6; D006655:Histone Deacetylases / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D016513:Mice, SCID; D008969:Molecular Sequence Data; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D054875:Ubiquitination
chemical_list: D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D006360:Heat-Shock Proteins; C000717248:Hspa5 protein, mouse; D046988:Proteasome Endopeptidase Complex; C433811:HDAC6 protein, human; D000073864:Histone Deacetylase 6; D006655:Histone Deacetylases