CONTROL OF THE SYNTHESIS OF A MAJOR POLYPEPTIDE OF CHLOROPLAST MEMBRANES IN <i>CHLAMYDOMONAS REINHARDI </i>

Hoober, J. Kenneth; Stegeman, William J.

doi:10.1083/jcb.56.1.1

Cited by 67 publications

(61 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In experiments designed to determine if any of the major chloroplast membrane polypeptides appeared first in a soluble form before their integration into the membrane, we examined the electrophoretic profile of the nonmembranous polypeptides and found no detectable group 1I polypeptides in the soluble fraction. This result suggests that, although it is likely that lib and IIc exist in a nonmembranous form since they are synthesized in the cytoplasm (11,17), the lamellar polypeptides must be integrated 770 THE JOURNAL OF CELL BIOLOGY . VOLUME 63,1974 into the membrane at high rates and that their nonmembranous existence must be extremely brief.…”

Section: P Beck and R P Levine Synthesis Of Chloroplast Membranmentioning

confidence: 96%

“…In the first procedure, cells were labeled for 1 h during the synchronous cycle simultaneously with After labeling during the synchronous cycle, samples of cells were harvested, washed, and disrupted by sonic oscillation, and the membranous fraction was obtained (32). Membrane polypeptides were analyzed by polyacrylamide gel electrophoresis by the methods described by Hoober, including extraction with 90% acetone to remove lipids and addition of mercaptoethanol to prevent oxidation of sulfhydryl groups (17). Gels were divided into 1-mm slices and radioactivity in the slices were measured by counting in tolueneOmnifluor containing 3% Protosol (New England Nuclear).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

SYNTHESIS OF CHLOROPLAST MEMBRANE POLYPEPTIDES DURING SYNCHRONOUS GROWTH OF CHLAMYDOMONAS REINHARDTII

Beck

Levine

1974

The Journal of Cell Biology

View full text Add to dashboard Cite

The synthesis of the major chloroplast membrane polypeptides has been studied during synchronous growth of Chlamydomonas reinhardtii. Under these conditions, chlorophyll is synthesized during the latter part of the light period and cell division takes place during the dark period. The profile of the chloroplast membrane polypeptides of C. reinhardtii has been well characterized and shown to contain two major classes by size (Hoober, J. 1970. J. Biol. Chem. 245:4327). Polypeptides of group I have a mol wt range of 50,000-55,000 daltons. The second region consists of at least three polypeptide groups, IIa, lib, and IIc, having mol wt of 40,000, 31,000, and 27,000 daltons, respectively. The synthesis of these polypeptides has been measured using a doublelabeling technique and a computer-aided statistical analysis. The rate of labeling of group I polypeptides is highest during the early light period and decreases after 6 h of growth. Group IIa is labeled from the beginning of the light period, but little synthesis of lib occurs before 3 h, and significant amounts of label are not found in IIc before 5 h of growth. After approximately 8 h of light, groups lib and IIc are synthesized at rates significantly greater than those of the other membrane polypeptides. The synthesis of the major polypeptide groups ceases in the dark. We conclude that the biosynthesis of the chloroplast membranes is a sequential or stepwise process.Much information has recently become available concerning the physical properties of biological membranes. Less, however, is known about the processes of synthesis and integration of components required for the production of functional membranes, especially in eukaryotic cells. First, it is not known whether there exists an obligatory coupling of the synthesis of one or more of the proteins and lipids involved in the formation of membranes under conditions of normal cell growth, and, second, it is not known whether the association of specific lipid and protein components is required for their integration into the membrane. With regard to the first question, experiments with bacterial mutants have indicated that the synthesis of membrane lipids and proteins is closely coordinated (1-4). On the other hand, the turnover of lipids and proteins of rat liver cell endoplasmic reticulum appears to occur at different rates (5, 6), and studies with the y-I mutant of Chlamydomonas reinhardtii have shown that the ratios of various chloroplast membrane components vary during the greening process (7 9). These results sug-

show abstract

Section: P Beck and R P Levine Synthesis Of Chloroplast Membranmentioning

confidence: 96%

Section: Methodsmentioning

confidence: 99%

SYNTHESIS OF CHLOROPLAST MEMBRANE POLYPEPTIDES DURING SYNCHRONOUS GROWTH OF CHLAMYDOMONAS REINHARDTII

Beck

Levine

1974

The Journal of Cell Biology

View full text Add to dashboard Cite

show abstract

“…Accordingly, the doublet polypeptides are associated with blocked chloroplast development both where the block is genetic and where it is environmental. Several investigators (5,6,7,17) have provided evidence, that at early stages of greening newly formed membrane proteins and chlorophyll are inserted into existing membranes, while at later stages synthesis of all membrane components takes place. Others have suggested that qualitatively all polypeptides are present prior to greeening and that functional photosynthetic membranes can be formed by reorganization as chlorophyll accumulates (10).…”

Section: Discussionmentioning

confidence: 99%

Polypeptide composition of internal membranes from barley etioplasts

Høyer‐Hansen

Machold²,

Kahn

1976

Carlsberg Res. Commun.

View full text Add to dashboard Cite

The polypeptides of isolated etioplast membranes and chloroplast membranes were solubilized in sodium dodecyl sulfate. Protein band patterns were obtained by electrophoresis on polyacrylamide slab gels with separating gels containing either a uniform polyacrylamide concentration or a concentration gradient. Several characteristic chloroplast bands were absent or reduced in intensity in patterns of etioplast membranes. Conversely, certain bands found in etioplast membrane patterns were reduced or absent in patterns of chloroplast membranes. Among these was a distinct doublet detected only in patterns of etioplast membrane polypeptides obtained with gels lacking urea. Some bands, for example those tentatively identified as subunits of coupling factor were found in patterns of etioplast as well as chIoroplast membranes.

show abstract

“…The stepwise addition of membrane com-I Max Bogen Research Fellow. 2 Recipient of the United States-Israel Science Foundation Grant 184. ponents in Chlamydomonas reinhardi was so far demonstrated for two classes of polypeptides (11,16) associated with the binding of Chl and the formation of the active centers of both photosystems (2,11,16). In addition, a developmental sequence of events related to the formation of P700 and light harvesting Chl has been described (10).…”

mentioning

confidence: 99%

Development of Photosystem II Complex during Greening of Chlamydomonas reinhardi y-1

Malkin¹,

Shochat²,

Ohad³

1976

Plant Physiol.

View full text Add to dashboard Cite

The relative content of organized pigment, active centers, and acceptor pools of photosystem II and their interconnection dunng the development of the photosynthetic membranes of Chlamydomonas reinhardi y-1 have been measured using the fluorescence induction technique. The degree of connectivity and efficiency of the developing system has been assessed also from measurements of maximal rates, quantum yield, and flash yield of 2,6-dichlorophenolindophenol photoreduction using H20 as the electron donor. The results obtained indicate that the process of membrane development in this organism consists of two phases: an initial phase of reorganization and connection between pre-existing components, and a second phase of actual accumulation of newly formed, complete, and active units. The ratio of active centers to Chl remains practically constant throughout the process while the degree of connectivity between the active center and the plastoquinone pool was doubled during the early phase of the greening. In addition the degree of connectivity between the plastoquinone pool and the rest of the electron transport chain increases as demonstrated by a 10-to 20-fold rise in the quantum yield and a 10-fold rise in the maximal rate and the flash yield. The ratio of light harvesting Chl to active centers remains apparently constant during the second phase of the greening as indicated by light saturation experiments and by the constancy of the apparent photosynthetic unit size. Electron donation from H20 seems to develop slower than the activity of the rest of the complex as demonstrated by measurements of 2,6-dichlorophenolindophenol photoreduction using 1,5-diphenylcarbazide as the electron donor. The value of all the above parameters which remain constant during the second phase of the greening are comparable to those obtained with membranes of light-grown cells.The process of chloroplast membrane biogenesis has been the subject of extensive work carried out in many laboratories. The results obtained so far have been reviewed recently (5,18,28). The process of assembly of components and membrane development can be summarized as follows. The chloroplast membranes grow by progressive insertion of newly formed components within pre-existing membranes. The addition of the new components can occur simultaneously or stepwise, and in the second case can result in continuous rearrangements and organizational changes within the membrane, detected at the ultrastructural level (17) and accompanied by drastic changes in photosynthetic activity (12,27,37 (10).The development of 02 evolution activity during greening of a dark-grown Chlorella mutant has been described by Herron and Mauzerall (15) and measurements of both activation of 02 evolution and variable fluorescence during greening of another Chlorella mutant have been reported by Dubertret and Joliot (7). The data obtained by both groups indicate that in these mutants active centers connected to the electron transport chain are present in the membrane at the very beginning...

show abstract

CONTROL OF THE SYNTHESIS OF A MAJOR POLYPEPTIDE OF CHLOROPLAST MEMBRANES IN CHLAMYDOMONAS REINHARDI

Cited by 67 publications

References 31 publications

SYNTHESIS OF CHLOROPLAST MEMBRANE POLYPEPTIDES DURING SYNCHRONOUS GROWTH OF CHLAMYDOMONAS REINHARDTII

SYNTHESIS OF CHLOROPLAST MEMBRANE POLYPEPTIDES DURING SYNCHRONOUS GROWTH OF CHLAMYDOMONAS REINHARDTII

Polypeptide composition of internal membranes from barley etioplasts

Development of Photosystem II Complex during Greening of Chlamydomonas reinhardi y-1

Contact Info

Product

Resources

About