E1A deregulates the centrosome cycle in a Ran GTPase-dependent manner.
By means of the yeast two-hybrid system, we have discovered a novel physical interaction between the adenovirus E1A oncoprotein and Ran, a small GTPase which regulates nucleocytoplasmic transport, cell cycle progression, and mitotic spindle organization. Expression of E1A elicits induction of S phase and centrosome amplification in a variety of rodent cell lines. The induction of supernumerary centrosomes requires functional RCC1, the nucleotide exchange factor for Ran and, hence, a functional Ran network. The E1A portion responsible for the interaction with Ran is the extreme NH(2)-terminal region (amino acids 1-36), which is also required for the induction of centrosome amplification. In an in vitro assay with recombinant proteins, wild-type E1A interferes with nucleotide exchange on Ran, whereas an E1A mutant, deleted from the extreme NH(2)-terminal region, does not. In addition, we detected an in vitro interaction between Ran and HPV-16 E7 and SV40 large T antigen, two oncoproteins functionally related to E1A. These findings suggest a common pathway of these oncoproteins in eliciting virus-induced genomic instability.
De Luca
Antonio
A
Department for the Development of Therapeutic Programs, Laboratory C, Regina Elena Cancer Institute, CRS, Rome, Italy.
Mangiacasale
Rosamaria
R
Severino
Anna
A
Malquori
Lorenzo
L
Baldi
Alfonso
A
Palena
Antonella
A
Mileo
Anna Maria
AM
Lavia
Patrizia
P
Paggi
Marco G
MG
D016475:3T3 Cells; D017500:Adenovirus E1A Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000378:metabolism; D018797:Cell Cycle Proteins; D002460:Cell Line; D018385:Centrosome / Q000502:physiology*; D006224:Cricetinae; D020662:Guanine Nucleotide Exchange Factors / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D009687:Nuclear Proteins; D009856:Oncogene Proteins, Viral / Q000378:metabolism; D050725:Papillomavirus E7 Proteins; D016196:S Phase / Q000502:physiology; D013347:Subcellular Fractions / Q000378:metabolism; D014162:Transfection; D020931:ran GTP-Binding Protein / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
D017500:Adenovirus E1A Proteins; D000952:Antigens, Polyomavirus Transforming; D018797:Cell Cycle Proteins; D020662:Guanine Nucleotide Exchange Factors; D009687:Nuclear Proteins; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; C062521:RCC1 protein, human; C499302:Rcc1 protein, mouse; C059731:oncogene protein E7, Human papillomavirus type 16; D020931:ran GTP-Binding Protein