The adaptor protein DCAF7 mediates the interaction of the adenovirus E1A oncoprotein with the protein kinases DYRK1A and HIPK2.
DYRK1A is a constitutively active protein kinase that has a critical role in growth and development which functions by regulating cell proliferation, differentiation and survival. DCAF7 (also termed WDR68 or HAN11) is a cellular binding partner of DYRK1A and also regulates signalling by the protein kinase HIPK2. DCAF7 is an evolutionarily conserved protein with a single WD40 repeat domain and has no catalytic activity. We have defined a DCAF7 binding motif of 12 amino acids in the N-terminal domain of class 1 DYRKs that is functionally conserved in DYRK1 orthologs from Xenopus, Danio rerio and the slime mold Dictyostelium discoideum. A similar sequence was essential for DCAF7 binding to HIPK2, whereas the closely related HIPK1 family member did not bind DCAF7. Immunoprecipitation and pulldown experiments identified DCAF7 as an adaptor for the association of the adenovirus E1A protein with DYRK1A and HIPK2. Furthermore, DCAF7 was required for the hyperphosphorylation of E1A in DYRK1A or HIPK2 overexpressing cells. Our results characterize DCAF7 as a substrate recruiting subunit of DYRK1A and HIPK2 and suggest that it is required for the negative effect of DYRK1A on E1A-induced oncogenic transformation.
Institute of Pharmacology and Toxicology, RWTH Aachen University, Aachen, Germany.
Florian
F
Glenewinkel
Departments of Microbiology &Immunology and Oncology, University of Western Ontario, London, Ontario, Canada.
Michael J
MJ
Cohen
Departments of Microbiology &Immunology and Oncology, University of Western Ontario, London, Ontario, Canada.
Cason R
CR
King
Institute of Pharmacology and Toxicology, RWTH Aachen University, Aachen, Germany.
Sophie
S
Kaspar
Institute of Pharmacology and Toxicology, RWTH Aachen University, Aachen, Germany.
Simone
S
Bamberg-Lemper
Departments of Microbiology &Immunology and Oncology, University of Western Ontario, London, Ontario, Canada.
Joe S
JS
Mymryk
Institute of Pharmacology and Toxicology, RWTH Aachen University, Aachen, Germany.
Walter
W
Becker
D048868:Adaptor Proteins, Signal Transducing / Q000502:physiology*; D017500:Adenovirus E1A Proteins / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D004023:Dictyostelium / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D010766:Phosphorylation; D011485:Protein Binding; D011487:Protein Conformation; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000737:chemistry / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism; D000097603:Dyrk Kinases
D048868:Adaptor Proteins, Signal Transducing; D017500:Adenovirus E1A Proteins; D002352:Carrier Proteins; D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases; D000097603:Dyrk Kinases; C515143:DCAF7 protein, human; C115114:HIPK2 protein, human