Chloroplast of Chlamydomonas

Ris H, Plaut W (1962) Ultrastructure of DNA-containing areas in the chloroplasts of Chlamydomonas. J Cell Biol 12 383-391... 

Rosales-Mendoza, S., Paz-Maldonado, L.M.T., Martfnez-Salgado, L., Guevara-Arauza, J.C., and Soria-Guerra, R.E. (2013) Production of milk-derived bioactive peptides as precursor chimeric proteins in chloroplasts of Chlamydomonas reinhardtii. Plant Cell Tissue Organ Cult, 1-9. 

Protein Import Into Chloroplasts of Chlamydomonas reinhardtii 823... 

Some plant HSPs are known to be associated with chloroplasts. Although chloroplasts and mitochondria do not synthesise HSP themselves (Nieto-Sotelo Ho, 1987), certain nuclear encoded HSPs synthesised in the cytosol have been shown to be transported into chloroplasts (Kloppstech et al., 1985 Vierling et al., 1986). The HSP22 of Chlamydomonas is incorporated into the thylakoid membrane without size reduction, while in pea, HSP22 is synthesised as a 26 kDa precursor. In Chlamydomonas, Schuster et al. (1988) have shown that the HSP22 is associated with the photosystem... 

However, cells of Chlamydomonas treated with ethidium bromide are able later to regenerate their chloroplast DNA. This result has been interpreted to mean that there may be one or a few "master copies" of chloroplast DNA in specially protected locations. The result should also be considered in relationship to the following observation. Although nuclear and organelle DNA molecules replicate at different times in the cell cycle, constant proportions of the organelle and nuclear DNA tend to be maintained. Thus, there must be some kind of control mechanism leading to a coupling of DNA replication in nuclei, mitochondria, and chloroplasts.465... 

Figure 4. Electron micrograph of longitudinal sections of Chlamydomonas reinhardtii Dang. A. Control cell B. Cell treated 1 h with 1.0-1.5 g/ml nonylphenol C. Chloroplast d. dichtyosome f. flagella m. mitochondrion mi. microtubules n. nucleus p. pyrenoid pi. plasmalemma.

Starch is formed in chloroplasts of moss, fern and green algae.18 Chlorophyceae (green algae) starch is similar to that of higher plants, and several species have been used in studies of starch biosynthesis.19,22,29 In a recent set of studies, Ball et al.22 used Chlamydomonas reinhardtii to study starch biosynthesis. They produced several Chlamydomonas mutants which produce starch with characteristics similar to starches produced by maize endosperm mutants.31-34 The various starch mutations of Chlamydomonas will be discussed in Section 3.7. Other classes of algae which produce starch are Prasinophyceae19,35 and Cryptophyceae.35,36... 

Park H and Hoober JK (1997) Chlorophyll synthesis modulates retention of apoproteins oflight-harvesting complex II by the chloroplast in Chlamydomonas reinhardtii. Physiol Plant 101 135-142... 

Kunstner P, Guardiola A, Takahashi Y et al. A mutant strain of Chlamydomonas reinhardtii lacking the chloroplast photosystem II psbl gene grows photoautotrophically. J Biol Chem 1995 270 9651-9654. 

Harris, E.H., Burkhart, B.D., Gillham, N.W, and Boynton, J.E. (1989) Antibiotic resistance mutations in the chloroplast 16S and 23S rRNA genes of Chlamydomonas reinhardtii correlation of genetic and physical maps of the chloroplast genome. Genetics, 123 (2), 281-292. 

Turmel M, Boulanger J, Lemieux C. Two group I intron with long internal open reading frames in the chloroplast psbA gene of Chlamydomonas reinhardtii. Nucleic Acids Res. 1989 17 3875-87. 

We have found the chlorophyll b-less cbn1-48 mutant of Chlamydomonas to be particularly helpful in highlighting some of the unique features of our new gel system, and in demonstrating how specific chlorophyll-protein complexes may relate to structural parameters of chloroplast membranes (Chunayev, et al., 1984). 

EXPRESSION OF THE CHLOROPLAST atpB GENE OF CHLAMYDOMONAS REINHARDTII IN E. COLI... 

ATP are located on the a and P subunits and the catalytic sites are thought to be on the p subunits. Isolated CFi is a latent ATPase which can be activated by a variety of means to exhibit a Mg2+- or a Ca +- dependent ATPase activity (1). Subunits a, P and e of CFi are encoded in the chloroplast DNA (2,3). The gene atpB from chloroplast DNA of Chlamydomonas reinhardtiU encoding for subunit P, was isolated and sequenced (4). We have subcloned the atpB gene into pT7-2 from plasmid pB7 (a gift from Dr. N. 

MANIPULATING THE CHLOROPLAST GENOME OF CHLAMYDOMONAS - - - MOLECULAR GENETICS AND TRANSFORMATION. 

The genes for ps1A2 and LS were resected from the cloned EcoRI fragment 15 of Chlamydomonas chloroplast DNA (7) and cloned into pGem and pT7-1 plasmid. RNA from the different plasmids was produced with T7 RNA-polymerase (BRL) according to the manufacturer, using plasmids linearized with restriction endonucleases as templates. 

BEHAVIOR OF CHLOROPLAST NUCLEOIDS DURING THE CELL CYCLE OF CHLAMYDOMONAS REINHARDTII IN SYNCHRONIZED CULTURE... 

The procedure for the isolation of chloroplasts from cell wall mutants of Chlamydomonas yields relatively pure, active chloroplasts. These chloroplast were photosynthetically active (3) and synthesized proteins in organello (4). They also imported, processed and assembled in vitro synthesized precursors for the small subunit of ribulose bisphosphate carboxylase and for the light harvesting chlorophyll a/b proteins (5, 6, 7). 

The nuclear encoded 22 kDa heat shock protein (hsp22) of Chlamydomonas is transported into the chloroplast, where it was localized in the grana thylakoids (9) and apparently protected PSII from photoinhibition (10). In contrast to most other imported proteins, hsp22 was not detected as a high molecular weight precursor in vitro. Therefore it does not have a precursor peptide and seems not to be processed during import in vivo (8). 

In this study we isolated chloroplasts of normal and heat shocked Chlamydomonas reinhardtii cells, PolyA-RNA was purified from heat shocked cells. In vitro translation products of this RNA were used to investigate import into chloroplasts derived from normal and heat-shocked cells. 

An association between photorespiration and the metabolism in chloroplasts of ammonia from protein catabolism has been shown with the alga Chlamydomonas. Evidence that increased oxygen stimulated this ammonia utilisation and carbon dioxide alone or anaerobiosis abolished it was obtained. The results were consistent with a close link between Rubisco s oxygenase activity and protein catabolism releasing ammonia, which was then reassimilated in the chloroplast. Results suggesting a similar link when nitrate was utilised by the cells were also obtained. Whether this link also exists in higher plants was not investigated. 

Expression of the Chloroplast atpB Gene of Chlamydomonas reinhardtii in E.coli 193... 

Manipulating the Chloroplast Genome of Chlamydomonas - Molecular Genetics and... 

Behavior of Chloroplast Nucleoids During the Cell Cycle of Chlamydomonas reinhardtii in Synchronized Culture 629... 

A rather thorough integration of the presumptive chloroplast precursors, the blue-green algae, when associated with a host cell, has been reported and the associated organelle has been called plastoid or cyanophors. In our laboratory, we tested ribosomes of Chlamydomonas reinhardtii chloroplasts, compared them with their cytoplasmic ribosomes, and found them positive for a specific function characteristic of a prokaryote ribosome, in contrast to their cytoplasmic counterparts. 

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