It is generally accepted that chloroplast was originated from a photosynthetic cyanobacterium by endosymbiosis. Recent findings indicated that a FtsZ like protein, which was the homologue of the essential prokaryotic ...It is generally accepted that chloroplast was originated from a photosynthetic cyanobacterium by endosymbiosis. Recent findings indicated that a FtsZ like protein, which was the homologue of the essential prokaryotic cell division protein, involved in the division of chloroplasts in plants. Using degenerate oligodeoxyribonucleotide primers based on conserved regions of the prokaryotic cell division protein FtsZ, a 570?bp cDNA fragment, named CrFtsZ 2, was isolated from Chlamydomonas reinhardtii by RT PCR. It was used to search the Chlamydomonas reinhardtii EST Database, and several contig EST sequences were found. The complete CrFtsZ 2 cDNA sequence was assembled by software and was amplified by RT PCR. With a 1?305?bp ORF(opening reading frame), the full length 1?815?bp CrFts Z cDNA had a 19?bp 5′UTR and a 490?bp 3′UTR. The CrFtsZ 2, which showed significant homology with other FtsZs , was a typical FtsZ gene, and encoded a precursor of 434 amino acid residues with a putative transit peptide in its N terminal. Phylogenetic tree of 23 FtsZs homologies reconstructed based on 300 conserved amino acid regions of the FtsZs suggested that CrFtsZ2 shared an ancestor probably with the FtsZ in cyanobacteria.展开更多
As an important group of plant cellular organelles, the molecular mechanism of plastid division is poorly understood. Recent studies have revealed that the homologs of ftsZ gene, an essential prokaryotic cell division...As an important group of plant cellular organelles, the molecular mechanism of plastid division is poorly understood. Recent studies have revealed that the homologs of ftsZ gene, an essential prokaryotic cell division gene, are involved in plastid division process of plant cells. Antisense and sense expression constructions were employed to investigate the functions of the two ftsZ genes, NtFtsZ1 and NtFtsZ2, in transgenic Nicotiana tabacum L. plants. Although antisense expression of,NtFtsZs reduced the native protein level obviously, the size and number of chloroplasts in transgenic tobacco plants had no effect. In contrast, overexpression of NtFtsZs in transgenic plants strikingly changed the number and morphology of chloroplasts. Even only 1 - 2 huge chloroplasts could be seen in the mesophyll cells of some overexpression transgenic plants. Analyses of chloroplast ultrastructures and chlorophyll content of different transgenic plants suggested that NtFtsZs gene have no direct influence on the normal development and function of chloroplasts. ne changes in chloroplast morphology must be a compensation for the change in chloroplast number. The different phenotypes of chloroplasts in antisense and sense transgenic plants implied that different members from the same ftsZ gene family may have similar function in controlling plastid division. Meanwhile, the changes of chloroplast morphology in sense transgenic plants represented the possible plastoskeleton function of ftsZ in higher plant.展开更多
Two plastid division genes, NtFtsZ1 and NtFtsZ2 isolated from Nicotiana tabacum L. were fused with gfp and expressed in Escherichia coli . The regular localizations of full length NtFtsZs∶GFP along the fil...Two plastid division genes, NtFtsZ1 and NtFtsZ2 isolated from Nicotiana tabacum L. were fused with gfp and expressed in Escherichia coli . The regular localizations of full length NtFtsZs∶GFP along the filamentous bacteria indicated that the NtFtsZs could recognize the potential division sites in E. coli and be polymerized with heterogeneous FtsZ from bacteria. The overexpression of NtFtsZs ∶ gfp inhibited the division of host strain cells and resulted in the long filamentous bacterial morphology. These results suggested that eukaryotic ftsZs have similar function to their prokaryotic homologs. Meanwhile, the different deletions of motifs of NtFtsZs are also employed to investigate the functions of these proteins in E. coli . The results showed that the C_terminal domains of NtFtsZs were related to the correct localization of NtFtsZs in E. coli and the N_terminal domains of NtFtsZs were responsible for the polymerization of homogeneous and heterogeneous FtsZ proteins. The significance of these results in understanding the functions of NtFtsZs in plastid division were discussed.展开更多
A nucleus-encoded MinE gene, designated PpMinE, from Physcomitrella patens was identified using RT-PCR. The presence of both N- and C-terminal extensions in PpMinE protein suggested its cyanobacterial origin. The tran...A nucleus-encoded MinE gene, designated PpMinE, from Physcomitrella patens was identified using RT-PCR. The presence of both N- and C-terminal extensions in PpMinE protein suggested its cyanobacterial origin. The transient expression of PpMinE using green fluorescent protein fusion in tobacco （Nicotiana tabacum L.） indicated that the PpMinE was a chloroplast-targeted protein. Overexpression of PpMinE in Escherichia coli caused division site misplacement and minicell formation, suggesting evolutionary functional conservation of MinE during plant phylogenesis. According to the phylogenetic tree, PpMinE protein has a close relationship with the highland plants, which suggests that the transfer events of MinE gene from plastid to nucleus might have occurred before the origin of the land plants.展开更多
基金国家自然科学基金 (No .GN3 9970 3 5 6)北京市自然科学基金 (No .GN5 992 0 0 3 )资助项目~~
文摘It is generally accepted that chloroplast was originated from a photosynthetic cyanobacterium by endosymbiosis. Recent findings indicated that a FtsZ like protein, which was the homologue of the essential prokaryotic cell division protein, involved in the division of chloroplasts in plants. Using degenerate oligodeoxyribonucleotide primers based on conserved regions of the prokaryotic cell division protein FtsZ, a 570?bp cDNA fragment, named CrFtsZ 2, was isolated from Chlamydomonas reinhardtii by RT PCR. It was used to search the Chlamydomonas reinhardtii EST Database, and several contig EST sequences were found. The complete CrFtsZ 2 cDNA sequence was assembled by software and was amplified by RT PCR. With a 1?305?bp ORF(opening reading frame), the full length 1?815?bp CrFts Z cDNA had a 19?bp 5′UTR and a 490?bp 3′UTR. The CrFtsZ 2, which showed significant homology with other FtsZs , was a typical FtsZ gene, and encoded a precursor of 434 amino acid residues with a putative transit peptide in its N terminal. Phylogenetic tree of 23 FtsZs homologies reconstructed based on 300 conserved amino acid regions of the FtsZs suggested that CrFtsZ2 shared an ancestor probably with the FtsZ in cyanobacteria.
文摘As an important group of plant cellular organelles, the molecular mechanism of plastid division is poorly understood. Recent studies have revealed that the homologs of ftsZ gene, an essential prokaryotic cell division gene, are involved in plastid division process of plant cells. Antisense and sense expression constructions were employed to investigate the functions of the two ftsZ genes, NtFtsZ1 and NtFtsZ2, in transgenic Nicotiana tabacum L. plants. Although antisense expression of,NtFtsZs reduced the native protein level obviously, the size and number of chloroplasts in transgenic tobacco plants had no effect. In contrast, overexpression of NtFtsZs in transgenic plants strikingly changed the number and morphology of chloroplasts. Even only 1 - 2 huge chloroplasts could be seen in the mesophyll cells of some overexpression transgenic plants. Analyses of chloroplast ultrastructures and chlorophyll content of different transgenic plants suggested that NtFtsZs gene have no direct influence on the normal development and function of chloroplasts. ne changes in chloroplast morphology must be a compensation for the change in chloroplast number. The different phenotypes of chloroplasts in antisense and sense transgenic plants implied that different members from the same ftsZ gene family may have similar function in controlling plastid division. Meanwhile, the changes of chloroplast morphology in sense transgenic plants represented the possible plastoskeleton function of ftsZ in higher plant.
文摘Two plastid division genes, NtFtsZ1 and NtFtsZ2 isolated from Nicotiana tabacum L. were fused with gfp and expressed in Escherichia coli . The regular localizations of full length NtFtsZs∶GFP along the filamentous bacteria indicated that the NtFtsZs could recognize the potential division sites in E. coli and be polymerized with heterogeneous FtsZ from bacteria. The overexpression of NtFtsZs ∶ gfp inhibited the division of host strain cells and resulted in the long filamentous bacterial morphology. These results suggested that eukaryotic ftsZs have similar function to their prokaryotic homologs. Meanwhile, the different deletions of motifs of NtFtsZs are also employed to investigate the functions of these proteins in E. coli . The results showed that the C_terminal domains of NtFtsZs were related to the correct localization of NtFtsZs in E. coli and the N_terminal domains of NtFtsZs were responsible for the polymerization of homogeneous and heterogeneous FtsZ proteins. The significance of these results in understanding the functions of NtFtsZs in plastid division were discussed.
基金This work was supported by the National Natural Science Foundation of China (No. 30470879).
文摘A nucleus-encoded MinE gene, designated PpMinE, from Physcomitrella patens was identified using RT-PCR. The presence of both N- and C-terminal extensions in PpMinE protein suggested its cyanobacterial origin. The transient expression of PpMinE using green fluorescent protein fusion in tobacco （Nicotiana tabacum L.） indicated that the PpMinE was a chloroplast-targeted protein. Overexpression of PpMinE in Escherichia coli caused division site misplacement and minicell formation, suggesting evolutionary functional conservation of MinE during plant phylogenesis. According to the phylogenetic tree, PpMinE protein has a close relationship with the highland plants, which suggests that the transfer events of MinE gene from plastid to nucleus might have occurred before the origin of the land plants.
