Jun Oka

Poly ADP-ribose glycohydrolase from rat liver nuclei, a novel enzyme degrading the polymer*

Summary A novel enzyme, poly ADP-ribose glycohydrolase, has been discovered and partially purified from rat liver nuclei. The enzyme catalyzes hydrolytic cleavage of the ribosyl (1 → 2) ribose bond between neighboring ADP-ribose units, but does not split the linkage by which the polymer is bound to protein. The activity is specifically inhibited by adenosine 3′,5′-cyclic monophosphate (cyclic AMP), the apparent Ki being around 1.5 m M . A kinetic study and product analyses have suggested that the glycohydrolase, rather than phosphodiesterase, plays a principal role in the degradation in situ of poly ADP-ribose.

Snake venom phosphodiesterase: Simple purification with Blue Sepharose and its application to poly(ADP-ribose) study☆

Abstract A rapid method of purifying snake venom phosphodiesterase has been developed using Blue Sepharose or blue dextran/Sepharose as an affinity adsorbent. A sixty-fold purification of the enzyme from commercial preparations is achieved in a single step with a yield of 60%. The purified enzyme preparation is essentially free from phosphatase activities and exhibits a major protein band on SDS-polyacrylamide gel electrophoresis. Chain length analysis of poly(ADP-ribose) exemplifies the usefulness of this technique.

Isolation and characterization of a cDNA for rat liver cysteine dioxygenase

Cysteine dioxygenase is a key enzyme of cysteine metabolism in mammals. The cDNA clones for rat liver cysteine dioxygenase were isolated by immunological screening and plaque hybridization from a rat liver cDNA library. The longest clone contained an insert of 1458 bp and encoded a polypeptide of 200 amino acids. The clone included the corresponding nucleotide sequence to amino acid sequences obtained from four lysyl endopeptidase-digested fragments of purified rat liver cysteine dioxygenase. The calculated molecular weight of rat liver cysteine dioxygenase was 23,025. Northern blot analysis revealed a single cysteine dioxygenase mRNA species of about 1.7 kb. A computer homology search indicated that this protein showed no homology with any known protein.

POLY(ADP-RIBOSE) AND ADP-RIBOSYLATION OF PROTEINS

Publisher Summary This chapter analyzes poly(ADP-ribose) and ADP-ribosylation of proteins. Poly(ADP-ribose) and the ADP-ribosylation of proteins constitute a novel type of covalent modification of proteins. They are ubiquitously distributed in nature and are implicated in the regulation of cell proliferation, protein synthesis, and DNA as well as RNA metabolism. This type of post-translational modification is unique because NAD, nicotinamide adenine dinucleotide, whose primary function is an electron carrier in biological oxidation, invariably provides the ADP-ribosyl moiety, which is transferred on to a protein molecule. The ADP-ribosyl unit thus, covalently attached to a protein acceptor is present as either a monomer or a polymer as in the case of the nuclear system. This chapter also summarizes developments in this field of research and some experimental results. It reviews briefly, mono ADP-ribosylation of proteins, in which only a single ADP-ribosyl moiety is transferred to a protein acceptor. It also covers a more complex reaction, poly(ADP-ribose) in nuclei, in which the ADP-ribosyl units are polymerized.

A new method for oligo(ADP-ribose) fractionation according to chain length☆

Abstract A new method was developed to separate mono- and oligo-(ADP-ribose) with chain lengths below 11 ADP-ribose units by size difference of one ADP-ribose residue. The separation was performed on a DEAE-cellulose column by elution with a NaCl gradient (0–0.3 M ) in the presence of 7 M urea at pH 7.6. Using this method, the chain length distribution of oligo(ADP-ribose) molecules attached to histones by incubation of isolated nuclei with radioactive NAD was determined. The average chain length estimated from this distribution coincided exactly with the value obtained by the phosphodiesterase digestion method, suggesting that the oligomers were synthesized directly on histones and not elongated from pre-existing ADP-ribose.

Immunological and Metabolic Reconstitution Following Successful Bone Marrow Transplantation from a HLA-Identical Sibling in an Infant with Adenosine Deaminase Deficeincy and Severe Combined Immunodeficiency: Partial Restoration of Purine Metabolism

Chen et al. have reported that bone marrow transplantation in a patient with adenosine deaminase (ADA) deficiency and severe combined immunodeficiency is followed by clearing of one abnormal metabolite, deoxy(d)ATP, from the patient’s own still ADA-deficient erythrocytes (1). This finding suggests that engraftment of donor lymphocytes into an ADA-deficient patient provided “enzyme replacement therapy”, and completely corrected the accumulation of adenine deoxyribonucleotides in one of nonlymphoid tissues.

5′-ADP-3″Deoxypentos-2″-Ulose. A Novel Product of ADP-Ribosyl Protein Lyase

Our previous studies [1, 2] revealed that the degradation of poly(ADP-ribosyl) proteins is carried out by consecutive actions of two enzymes, poly(ADP-ribose) glycohydrolase [3, 4] and ADP-ribosyl protein lyase (formerly termed ADP-ribosyl histone splitting enzyme) [5] (Fig. 1). The latter enzyme catalyzes removal of the last proximal ADP-ribosyl residue from acceptor protein. This report presents, after a brief review of ADP-ribosyl histones and the lyase, the identification of the enzymatic split product as a novel sugar derivative, and discusses its significance in poly(ADP-ribosyl) protein metabolism.

Regulation of the Cytosol 5′-Nucleotidase of the Heart by Adenylate Energy Charge

Adenosine formed by the heart has been proposed to participate in the metabolic regulation of coronary blood flow [1]. Adenosine can be formed from AMP by action of 5′-nucleotidase or alkaline or acid phosphatase, or from S-adenosylhomocysteine by means of S-adenosyl-homocysteine hydrolase. A 5′-Nucleotidase in the heart was shown by histochemical studies to be associated with myocardial cell membrane [2], and functional studies indicate the enzyme to be an ectoenzyme [3].

3-Deoxy-D-glycero-pentos-2-ulose, A Novel Pentose Derived from Poly(ADP-Ribosyl) Histories

Publisher Summary This chapter discusses ADP-ribosylation, which is a novel type of posttranslational covalent modification of proteins using NAD as a donor of the modification group. ADP-ribosylation reactions are classified into two major groups: mono- and poly(ADP-ribosyl)ation. Both types are distributed widely among eukaryotes and prokaryotes. Among a number of nuclear proteins known to serve as acceptors of poly(ADP-ribosyl)ation, histones have been studied most extensively in vitro as and in vivo . All of five major subfractions of histone—HI, H2A, H2B, H3, and H4—are ADP-ribosylated, although to different degrees. Degradation of poly(ADP-ribosyl) protein is carried out by three enzymes. Poly(ADP-ribose) glycohydrolase hydrolyzes the ribosyl- ribose bond inside the polymer to yield ADP-ribose; phosphodiesterase in mammalian cell nuclei hydrolyzes the pyrophosphate bond in the polymer and monomer of ADP-ribose to yield iso-ADPribose and AMP; and ADP-ribosyl protein lyase, which was formerly termed ADP-ribosyl histone splitting enzyme or, erroneously, ADP-ribosyl histone hydrolase, splits the linkage between ADP-ribose and protein. Evidence has been accumulating that suggests roles of poly(ADP-ribosyl)ation of nuclear proteins in DNA repair, cell differentiation, and oncogenesis. Condensation or decondensation of chromatin induced by poly(ADP-ribosyl)ation of histones and modifications of some enzyme activities by poly(ADP-ribosyl)ation or poly(ADP-ribose) have been postulated as the underlying mechanisms of these functions.