title: Mutation of androgen receptor N-terminal phosphorylation site Tyr-267 leads to inhibition of nuclear translocation and DNA binding.
abstract: Reactivation of androgen receptor (AR) may drive recurrent prostate cancer in castrate patients. Ack1 tyrosine kinase is overexpressed in prostate cancer and promotes castrate resistant xenograft tumor growth and enhances androgen target gene expression and AR recruitment to enhancers. Ack1 phosphorylates AR at Tyr-267 and possibly Tyr-363, both in the N-terminal transactivation domain. In this study, the role of these phosphorylation sites was investigated by characterizing the phosphorylation site mutants in the context of full length and truncated AR lacking the ligand-binding domain. Y267F and Y363F mutants showed decreased transactivation of reporters. Expression of wild type full length and truncated AR in LNCaP cells increased cell proliferation in androgen-depleted conditions and increased colony formation. However, the Y267F mutant of full length and truncated AR was defective in stimulating cell proliferation. The Y363F mutant was less severely affected than the Y267F mutant. The full length AR Y267F mutant was defective in nuclear translocation induced by androgen or Ack1 kinase. The truncated AR was constitutively localized to the nucleus. Chromatin immunoprecipitation analysis showed that it was recruited to the target enhancers without androgen. The truncated Y267F AR mutant did not exhibit constitutive nuclear localization and androgen enhancer binding activity. These results support the concept that phosphorylation of Tyr-267, and to a lesser extent Tyr-363, is required for AR nuclear translocation and recruitment and DNA binding and provide a rationale for development of novel approaches to inhibit AR activity.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States of America.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Karaca
authors.affiliation: Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States of America; Department of Hematology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China.
authors.forename: Yuanbo
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States of America.
authors.forename: Zhentao
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States of America.
authors.forename: Dinuka
authors.initials: D
authors.lastname: De Silva
authors.affiliation: Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States of America; Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America.
authors.forename: Joel S
authors.initials: JS
authors.lastname: Parker
authors.affiliation: Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States of America; Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America; Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America.
authors.forename: H Shelton
authors.initials: HS
authors.lastname: Earp
authors.affiliation: Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States of America; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States of America; Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America.
authors.forename: Young E
authors.initials: YE
authors.lastname: Whang
mesh_terms: D021581:Active Transport, Cell Nucleus; D001665:Binding Sites; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008297:Male; D010766:Phosphorylation; D017354:Point Mutation; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D011944:Receptors, Androgen / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: C410798:AR protein, human; D011944:Receptors, Androgen; D004247:DNA