Open AccessIdentification of a high molecular weight polypeptide that may be part of the circadian clockwork in Acetabularia
Author(s) -
R. Hartwig,
Manfred Schweiger,
Regina Schweiger,
Hans−Georg Schweiger
Publication year - 1985
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.82.20.6899
Subject(s) - acetabularia , cycloheximide , circadian rhythm , biology , protein biosynthesis , chloramphenicol , ribosome , euglena gracilis , darkness , endogeny , chloroplast , biochemistry , microbiology and biotechnology , rna , botany , endocrinology , gene , antibiotics
In the chloroplast fraction of the unicellular and uninucleate green algaAcetabularia , we have detected aMr ≈230,000 protein (p230) whose synthesis exhibits a pronounced endogenous diurnal rhythm. As judged by scanning densitometry of fluorographs of NaDodSO4 /polyacrylamide gels, the synthesis of other proteins in the same fraction was independent of the time in the cycle. The incorporation of [35 S]methionine into p230 was completely inhibited by cycloheximide, whereas chloramphenicol had no effect. This strongly suggests that p230 is translated on 80S ribosomes. Eighthour periods of exposure to cycloheximide produced a shift in the phase of the oscillation of p230 synthesis. The results are consistent with the hypothesis that p230 is essential for expression of circadian rhythms inAcetabularia .