Novel adenosine 3 prime ,5 prime -cyclic monophosphate dependent protein kinases in a marine diatom

Journal Article · Tue Aug 08 00:00:00 EDT 1989 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00442a014· OSTI ID:5353289

Lin, P P.C.; Volcani, B E ^[1]

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1. Univ. of California, San Diego, La Jolla (USA)

Two novel adenosine 3{prime},5{prime}-cyclic monophosphate (cAMP) dependent protein kinases have been isolated from the diatom Cylindrotheca fusiformis. The kinases, designated I and II, are eluted from DEAE-Sephacel at 0.10 and 0.15 M NaCl. They have a high affinity for cAMP and are activated by micromolar cAMP. They exhibit maximal activity at 5 mM Mg{sup 2+} and pH 8 with the preferred phosphate donor ATP and phosphate acceptor histone H1. They phosphorylate sea urchin sperm histone H1 on a single serine site in the sequence Arg-Lys-Gly-Ser({sup 32}P)-Ser-Asn-Ala-Arg and have an apparent M{sub r} of 75,000 as determined by gel filtration and sucrose density sedimentation. In the kinase I preparation a single protein band with an apparent M{sub r} of about 78,000 is photolabeled with 8-azido({sup 32}P)cAMP and is also phosphorylated with ({gamma}-{sup 32}P)ATP in a cAMP-dependent manner, after autoradiography following sodium dodecyl sulfate gel electrophoresis. The rate of phosphorylation of the 78,000-dalton band is independent of the enzyme concentration. The results indicate that (i) these diatom cAMP-dependent protein kinases are monomeric proteins, possessing both the cAMP-binding regulatory and catalytic domains on the same polypeptide chain, (ii) the enzymes do not dissociate into smaller species upon activation by binding cAMP, and (iii) self-phosphorylation of the enzymes by an intrapeptide reaction is cAMP dependent. The two diatom cAMP kinases are refractory to the heat-stable protein kinase modulator from rabbit muscle, but they respond differently to proteolytic degradation and to inhibition by arachidonic acid and several microbial alkaloids.

• OSTI ID: 5353289
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 28:16; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALGAE
AMP
AQUATIC ORGANISMS
ATP
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHROMOPHYCOTA
DAYS LIVING RADIOISOTOPES
DIATOMS
ELECTROPHORESIS
ENZYME ACTIVITY
ENZYMES
HYDROGEN COMPOUNDS
ISOTOPES
KINETICS
LIGHT NUCLEI
MOLECULAR STRUCTURE
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHORYLATION
PHOSPHOTRANSFERASES
PLANKTON
PLANTS
RADIOISOTOPES
REACTION KINETICS
TRANSFERASES
TRITIUM COMPOUNDS