Chloroplasts origin

Douglas SE. Chloroplast origins and evolution. In Bryant A, ed. The Molecular Biology of Cyanobacteria. Amsterdam Kluwer, 1994 91-118. 

Table I. Positional distribution of fatty acids in leaf glyceroliplds. The positional distribution was determined after digestion with RAizopuslipase. The presence of 16 carbon fatty acids at position sn-2 indicates chloroplastic origin of the DAG. The presence of 16 carbon fatty acids at position sn-1 is indicative of cytoplasmic origin of the DAG.

For the first step of the analysis of PSI biogenesis, we determined which subunits of PSI are nuclear-encoded. PSI complex was prepared from several species of Nicotiana, and each subunit was separated by high resolution LDS PAGE. Partial amino acid sequences were determined for each subunit, and compared with the amino acid sequences deduced from tobacco chloroplast DNA sequence in order to determine which subunits are chloroplast-encoded. As far as the PSI subunits having mol. wt. from 5.6 kDa to 20 kDa are concerned, it was only psaC protein that was proved to be of chloroplast origin. All the others, some of which are blocked at their N termini, are not coded for by chloroplast DNA, indicating that they are of nuclear origin. 

Considering that most of the PSII subunits are of chloroplast origin, it is a characteristic of the PSI complex that its biogenesis is largely dependent on the nuclear genome. 

But as IE is also in close reverse dependence on partial pressure of CO2 in the air (rises with the decrease in partial pressure) /7, 12/ which mesns that isoprene synthesis in which acetyl CoA of chloroplast origin is used is obviously mediated by the connection with the reaction of photosynthetic carboxylation. 

Kropat J, Oster U, Rudiger W, Beck CF. Chlorophyll precursors are signals of chloroplast origin involved in light induction of nuclear heat-shock genes. Proc Natl Acad Sci USA. 1997 94 14168-14172. 

Fig. 31. Schematic representation of the modulation of membrane composition and activity during membrane formation under different experimental conditions. The term Ur-membrane designates the basic membrane structure composed of L proteins of cytoplasmic origin and lipids which might serve as an obligatory acceptor frame for the additions of chlorophyll and activation proteins of chloroplast origin.

---