Identification of cancer-associated missense mutations in hace1 that impair cell growth control and Rac1 ubiquitylation.
The E3 ubiquitin ligase HACE1 is a potent tumor suppressor that controls cell proliferation and ubiquitylates the small GTPase Rac1 to target it to proteasomal degradation. Whether and how the activity of HACE1 is regulated by the N-terminal ankyrin (ANK) and the middle (MID) domains is ill defined. Here, we identified in the version 64 of the Catalogue of Somatic Mutations in Cancer (COSMIC) 13 missense mutations of hace1 located outside the HECT domain, and found that all lead to defective control of cell proliferation. In addition, several mutations located in the ankyrin domain displayed a dramatic reduction in Rac1 ubiquitylation associated with a decrease of colony formation in soft agar. 3D structure modelling of the 7 ankyrin-repeats coupled to functional analysis identified a surface epitope centered on one of the mutated residue, Gly-175, which is critical for controlling Rac1 binding and ubiquitylation. We also identified a role for the MID domain in conferring the specificity of association of HACE1 to the active form of Rac1. Our study of the functional interplay between HACE1 and Rac1 in cancer thus sheds a new light on the molecular mechanism of Rac1 ubiquitylation by HACE1 and the impact of its cancer-associated mutations in cell proliferation.
Inserm, U1065, C3M, Team Bacterial Toxins in Host-Pathogens Interactions France, Equipe labellisée la ligue contre le cancer, Nice 06204, France.|Université Nice Côte d'Azur, Inserm, C3M, France.
Emilie
E
Andrio
Inserm, U1065, C3M, Team Bacterial Toxins in Host-Pathogens Interactions France, Equipe labellisée la ligue contre le cancer, Nice 06204, France.|Université Nice Côte d'Azur, Inserm, C3M, France.|Laboratoire de Bactériologie, CHU de Nice, Hôpital l'Archet, Nice, France.
Romain
R
Lotte
Inserm, U1065, C3M, Team Bacterial Toxins in Host-Pathogens Interactions France, Equipe labellisée la ligue contre le cancer, Nice 06204, France.|Université Nice Côte d'Azur, Inserm, C3M, France.
Daniel
D
Hamaoui
Laboratoire de Biologie et Pharmacologie Appliquée, CNRS et Ecole Normale Supérieure Paris-Saclay, Université Paris-Saclay, Cachan, France.
Jacqueline
J
Cherfils
Inserm, U1065, C3M, Team Bacterial Toxins in Host-Pathogens Interactions France, Equipe labellisée la ligue contre le cancer, Nice 06204, France.|Université Nice Côte d'Azur, Inserm, C3M, France.
Anne
A
Doye
Vancouver Prostate Center, Vancouver, British Columbia, Canada.|Department of Urologic Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
Mads
M
Daugaard
Department of Molecular Oncology, British Columbia Cancer Research Center, Vancouver, Canada.
Poul H
PH
Sorensen
Université Nice Côte d'Azur, Inserm, C3M, France.|Inserm U1065, C3M, Team Cellular and Molecular Physiopathology of Obesity and Diabetes, Nice 06204, France.
Frédéric
F
Bost
Inserm, U1065, C3M, Team Bacterial Toxins in Host-Pathogens Interactions France, Equipe labellisée la ligue contre le cancer, Nice 06204, France.|Université Nice Côte d'Azur, Inserm, C3M, France.|Laboratoire de Bactériologie, CHU de Nice, Hôpital l'Archet, Nice, France.
Raymond
R
Ruimy
Inserm, U1065, C3M, Team Bacterial Toxins in Host-Pathogens Interactions France, Equipe labellisée la ligue contre le cancer, Nice 06204, France.|Université Nice Côte d'Azur, Inserm, C3M, France.
Amel
A
Mettouchi
Inserm, U1065, C3M, Team Bacterial Toxins in Host-Pathogens Interactions France, Equipe labellisée la ligue contre le cancer, Nice 06204, France.|Université Nice Côte d'Azur, Inserm, C3M, France.
Emmanuel
E
Lemichez
D000595:Amino Acid Sequence; D002460:Cell Line; D049109:Cell Proliferation; D006801:Humans; D008958:Models, Molecular; D050505:Mutant Proteins / Q000737:chemistry; D020125:Mutation, Missense / Q000235:genetics*; D009369:Neoplasms / Q000235:genetics*; D011485:Protein Binding; D000072417:Protein Domains; D013329:Structure-Activity Relationship; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D054875:Ubiquitination; D020830:rac1 GTP-Binding Protein / Q000378:metabolism*
D050505:Mutant Proteins; C497506:HACE1 protein, human; D044767:Ubiquitin-Protein Ligases; D020830:rac1 GTP-Binding Protein