This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Monroy, A. F. Articles by Schiff, J. A. Search for Related Content PubMed PubMed Citation Articles by Monroy, A. F. Articles by Schiff, J. A. Agricola Articles by Monroy, A. F. Articles by Schiff, J. A.

Articles

Photocontrol of Chloroplast and Mitochondrial Polypeptide Levels in Euglena¹

School of Biological Sciences, University of Nebraska, Lincoln, Nebraska 68588, Photobiology Institute, Brandeis University, Waltham, Massachusetts 02254

Two dimensional polyacrylamide gel electrophoresis resolved protein from intact chloroplasts of wild type Euglena gracilis Klebs var. bacillaris Cori into 185 polypeptides of which 55 were localized on the whole cell polypeptide map. Of these chloroplast polypeptides, the relative amounts of 49 increased, the relative amounts of two decreased, and the relative amounts of four polypeptides were unaltered by exposure of dark grown resting cells to light for 72 hours. Proteins from intact purified mitochondria obtained from a bleached mutant (W₁₀BSmL) lacking plastids were resolved into 193 polypeptides of which 44 were localized on the whole cell polypeptide map from wild type cells. Of these mitochondrial polypeptides, the relative amount of one increased, the relative amounts of 12 were unaltered, and the relative amounts of 31 decreased after exposure of the dark grown resting cells to light. Since it is known that the development of the chloroplast in Euglena occurs without a net increase in total cellular protein and without a change in the size of the cellular amino acid pools, the degradation of mitochondrial polypeptides represents a major source of amino acids for the synthesis of chloroplast polypeptides.

³ Abraham and Etta Goodman Professor of Biology.

¹ Supported by National Science Foundation grant PCM 8202472 to S. D. S. and by National Institutes of Health grant GM 14595 and National Science Foundation grant PCM 7918142 to J. A. S.