Cytoplasmic poly(ADP-ribose) polymerase and poly(ADP-ribose) glycohydrolase in AEV-transformed chicken erythroblasts.
Poly(ADP-ribose) polymerase and poly(ADP-ribose) glycohydrolase activities were both investigated in chicken erythroblasts transformed by Avian Erythroblastosis Virus. Respectively 21% and 58% of these activities were found to be present in the post-mitochondrial supernatant (PMS). Fractionation of the PMS on sucrose gradients and poly(A+) mRNA detection by hybridization to [3H] poly(U) show that cytoplasmic poly(ADP-ribose) polymerase is exclusively localized in free mRNP. The glycohydrolase activity sedimented mostly in the 6 S region but 1/3 of the activity was in the free mRNP zone. Seven poly(ADP-ribose) protein acceptors were identified in the PMS in the Mr 21,000-120,000 range. The Mr 120,000 protein corresponds to automodified poly(ADP-ribose) polymerase. A Mr 21,000 protein acceptor is abundant in PMS and a Mr 34,000 is exclusively associated with ribosomes and ribosomal subunits. The existence of both poly(ADP-ribose) polymerase and glycohydrolase activities in free mRNP argues in favour of a role of poly(ADP-ribosylation) in mRNP metabolism. A possible involvement of this post translational modification in the mechanisms of repression-derepression of mRNA is discussed.
Thomassin
H
H
Centre de Neurochimie du CNRS 5, Strasbourg, France.
Martins de Sa
C
C
Scherrer
K
K
Maniez
C
C
Mandel
P
P
D000818:Animals; D001354:Avian Leukosis Virus; D002472:Cell Transformation, Viral; D002645:Chickens; D003593:Cytoplasm / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D004900:Erythroblasts / Q000201:enzymology* / Q000382:microbiology; D006026:Glycoside Hydrolases / Q000097:blood*; D011065:Poly(ADP-ribose) Polymerases / Q000097:blood*; D013347:Subcellular Fractions / Q000201:enzymology; D014407:Tumor Cells, Cultured / Q000201:enzymology / Q000382:microbiology
D011065:Poly(ADP-ribose) Polymerases; D006026:Glycoside Hydrolases; C022407:poly ADP-ribose glycohydrolase