Abstract
Human poly(ADP-ribose) synthetase consists of three proteolytically separable domains, the first for binding of DNA, the second for automodification, and the third for binding of the substrate, NAD (Ushiro, H., Yokoyama, Y., and Shizuta, Y. (1987) J. Biol. Chem. 262, 2352-2357). We have isolated and sequenced cDNA clones for the enzyme using synthesized oligodeoxyribonucleotide probes based on the partial amino acid sequence of the protein. The open reading frame determined encodes a protein of 1,013 amino acid residues with a molecular weight of 113,203. The deduced amino acid sequence is consistent with the partial amino acid sequences of tryptic or alpha-chymotryptic peptides and the total amino acid composition of the purified enzyme. The native enzyme is relatively hydrophilic as judged from the hydrophilicity profile of the total amino acid sequence. The net charge of the NAD binding domain is neutral but the DNA binding domain and the automodification domain are considerably rich in lysine residue and quite basic. The DNA binding domain involves a homologous repeat in the sequence and exhibits a sequence homology with localized regions of transforming proteins such as c-fos and v-fos. Furthermore, this domain contains a unique sequence element which resembles the essential peptide sequences for nuclear location of SV40 and polyoma virus large T antigens. These facts suggest the possibility that the physiological function of poly(ADP-ribose) synthetase lies in its ability to bind to DNA and to control transformation of living eukaryotic cells like the cases of those oncogene products.
Highlights
From the $Department of Medical Chemistry, Kochi Medical School, Nankoku, Kochi 781-51,Japan, the §Department of Enzyme Chemistry, Institute for Enzyme Research, School of Medicine, the University of Tokushima, Tokushima 770, Japan, the VDepartment of Biochemistry, Miyazaki Medical College, Miyazaki 889-16.Japan,and the llPhurmaceutica1Institute, Keio University School of Medicine, Tokyo 160,Japan
Tryptic peptides and the total amino acidcomposition pates in these important biological mechanisms and how the of the purified enzyme.The native enzymiserelatively gene for poly(ADP-ribose) synthetase is regulated in eukarhydrophilic as judged from the hydrophilicity profile yotic cells remain to be elucidated
In order to provide an of the total amino acsiedquence
Summary
Poly(ADP-ribose) synthetase, an enzyme localized in the nucleus of eukaryotic cells, catalyzes the polymerization of the ADP-ribose moiety oNf AD to form a bipolymer, poly(ADP-ribose), which is covalently bound to various nuclear proteins [1,2]. The N-terminal human placenta[8].the aminaocid composition sequence of Ala-Ser as well as thatof Ala-Pro was suggested of the enzyme as deduced fromthe cDNA sequence reasonably by peptideanalysis of the 72-kDa fragmentas described agrees with that experimentally determined (Tabl1e11). Northern Blot Analysis of the mRNA-To determine the tide bondbetween residues 372-373 as well as thosebetween size of the mRNA encoding poly(ADP-ribose) synthetase, a residues 362-363, residues 374-375, and residues 382-383, series of Northern hybridization experimentswere performed resulting in the formation of microheterogeneous fragments usingpoly(A)+RNA from human placenta and restriction of 72 kDa. Based on thisconclusion in addition to our earlier fragments of the cDNA inserts of clones pPARS1, pPARS21, observations (7, 8, l l ) , it is reasonable to consider that the cDNA Sequence for Poly(ADSPy-nritbhoestea)se
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
