title: GADD45α and γ interaction with CDK11p58 regulates SPDEF protein stability and SPDEF-mediated effects on cancer cell migration.
abstract: The epithelium-specific Ets transcription factor, SPDEF, plays a critical role in metastasis of prostate and breast cancer cells. While enhanced SPDEF expression blocks migration and invasion, knockdown of SPDEF expression enhances migration, invasion, and metastasis of cancer cells. SPDEF expression and activation is tightly regulated in cancer cells; however, the precise mechanism of SPDEF regulation has not been explored in detail. In this study we provide evidence that the cell cycle kinase CDK11p58, a protein involved in G2/M transition and degradation of several transcription factors, directly interacts with and phosphorylates SPDEF on serine residues, leading to subsequent ubiquitination and degradation of SPDEF through the proteasome pathway. As a consequence of CDK11p58 mediated degradation of SPDEF, this loss of SPDEF protein results in increased prostate cancer cell migration and invasion. In contrast, knockdown of CDK11p58 protein expression by interfering RNA or SPDEF overexpression inhibit migration and invasion of cancer cells. We demonstrate that CDK11p58 mediated degradation of SPDEF is attenuated by Growth Arrest and DNA damage-inducible 45 (GADD45) α and , two proteins inducing G2/M cell cycle arrest. We show that GADD45 α and γ, directly interact with CDK11p58 and thereby inhibit CDK11p58 activity, and consequentially SPDEF phosphorylation and degradation, ultimately reducing prostate cancer cell migration and invasion. Our findings provide new mechanistic insights into the complex regulation of SPDEF activity linked to cancer metastasis and characterize a previously unidentified SPDEF/CDK11p58/GADD45α/γ pathway that controls SPDEF protein stability and SPDEF-mediated effects on cancer cell migration and invasion.
authors.affiliation: International Centre for Genetic Engineering and Biotechnology (ICGEB), Medical Biochemistry Division, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
authors.forename: Rodrigo E
authors.initials: RE
authors.lastname: Tamura
authors.affiliation: International Centre for Genetic Engineering and Biotechnology (ICGEB), Medical Biochemistry Division, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
authors.forename: Juliano D
authors.initials: JD
authors.lastname: Paccez
authors.affiliation: International Centre for Genetic Engineering and Biotechnology (ICGEB), Medical Biochemistry Division, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
authors.forename: Kristal C
authors.initials: KC
authors.lastname: Duncan
authors.affiliation: International Centre for Genetic Engineering and Biotechnology (ICGEB), Medical Biochemistry Division, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
authors.forename: Mirian G
authors.initials: MG
authors.lastname: Morale
authors.affiliation: BIDMC Genomics, Proteomics, Bioinformatics and Systems Biology Center, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
authors.forename: Fernando M
authors.initials: FM
authors.lastname: Simabuco
authors.affiliation: BIDMC Genomics, Proteomics, Bioinformatics and Systems Biology Center, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
authors.forename: Simon
authors.initials: S
authors.lastname: Dillon
authors.affiliation: Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA.
authors.forename: Ricardo G
authors.initials: RG
authors.lastname: Correa
authors.affiliation: BIDMC Genomics, Proteomics, Bioinformatics and Systems Biology Center, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
authors.forename: Xuesong
authors.initials: X
authors.lastname: Gu
authors.affiliation: BIDMC Genomics, Proteomics, Bioinformatics and Systems Biology Center, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
authors.forename: Towia A
authors.initials: TA
authors.lastname: Libermann
authors.affiliation: International Centre for Genetic Engineering and Biotechnology (ICGEB), Medical Biochemistry Division, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
authors.forename: Luiz F
authors.initials: LF
authors.lastname: Zerbini
mesh_terms: D017209:Apoptosis; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002465:Cell Movement; D049109:Cell Proliferation; D056743:Cyclin D3 / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008297:Male; D009687:Nuclear Proteins / Q000378:metabolism*; D010766:Phosphorylation; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000473:pathology*; D060066:Protein Interaction Maps; D055550:Protein Stability; D059748:Proteolysis; D050783:Proto-Oncogene Proteins c-ets / Q000737:chemistry* / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D000097642:GADD45 Proteins
chemical_list: D018797:Cell Cycle Proteins; D056743:Cyclin D3; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D050783:Proto-Oncogene Proteins c-ets; C534696:CCND3 protein, human; C439070:GADD45A protein, human; D000097642:GADD45 Proteins; C485654:GADD45G protein, human; C403974:SPDEF protein, human
keywords: CDK11p58; GADD45; SPDEF; invasion; migration