title: Annexin A1 is regulated by domains cross-talk through post-translational phosphorylation and SUMOYlation.
abstract: Mouse prostate membrane-associated proteins of the annexin family showed changes in SUMOylation during androgen treatment. Among these the calcium-binding annexin A1 protein (ANXA1) was chosen for further characterization given its role in protein secretion and cancer. SUMOylation of ANXA1 was confirmed by overexpressing SUMO-1 in LNCaP cells. Site-directed mutagenesis indicated that K257 located in a SUMOylation consensus motif in the C-terminal calcium-binding DA3 repeat domain is SUMOylated. Mutation of the N-terminal Y21 decreased markedly the SUMOylation signal while EGF stimulation increased ANXA1 SUMOylation. A structural analysis of ANXA1 revealed that K257 is located in a hot spot where Ca(2+) and SUMO-1 bind and where a nuclear export signal and a polyubiquitination site are also present. Also, Y21 is buried inside an α-helix structure in the Ca(2+)-free conformation implying that Ca(2+) binding, and the subsequent expelling of the N-terminal α-helix in a disordered conformation, is permissive for its phosphorylation. These results show for the first time that SUMOylation can be regulated by an external signal (EGF) and indicate the presence of a cross-talk between the N-terminal and C-terminal domains of ANXA1 through post-translational modifications.
authors.affiliation: Department of Pediatrics, Laboratory of Cellular Biology, Centre de recherche du CHUQ Centre-Mère-Enfant Soleil, Canada.
authors.forename: Danielle
authors.initials: D
authors.lastname: Caron
authors.forename: Halim
authors.initials: H
authors.lastname: Maaroufi
authors.forename: Sébastien
authors.initials: S
authors.lastname: Michaud
authors.forename: Robert M
authors.initials: RM
authors.lastname: Tanguay
authors.forename: Robert L
authors.initials: RL
authors.lastname: Faure
mesh_terms: D000818:Animals; D017305:Annexin A1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008297:Male; D051379:Mice; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation / Q000235:genetics*; D011467:Prostate / Q000166:cytology / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D058207:Sumoylation / Q000235:genetics*; D054875:Ubiquitination / Q000235:genetics
chemical_list: D017305:Annexin A1
keywords: 1-DE; 2-DE; 5α-dihydrotestosterone; ANXA1; Annexin A1; DHT; EGF receptor; EGFR; GDX; LNCaP; Membranes; SUMO; SUMOylation; annexin A1; gonadectomized; one-dimensional gel electrophoresis; prostate carcinoma cell line; small ubiquitin-related modifier; two-dimensional gel electrophoresis