Reversibility of peroxisomal differentiation in higher plants.

高等植物中过氧化物酶体分化的可逆性。

基本信息

批准号：
15207005
负责人：
NISHIMURA Mikio
金额：
$ 31.7万
依托单位：
National Institute for Basic Biology (2004-2005)Okazaki National Research Institutes (2003)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

Peroxisomes in higher plantcells are known to differentiate in function depending on the cell type. By a comprehensive survey of peroxisomal genes in the entire Arabidopsis genome, we found 286 candidates of peroxisomal genes. They included all genes for peroxisomal enzymes reported up to date, and most of them encoded functionally unknown proteins in peroxisomes. Analyses of gene expression profiles revealed that peroxisomal differentiation is caused by the expression of specific genes that are induced in specific organs in addition to constitutively expressed genes. The clustering analyses suggested that basic functions of peroxisomewereβ-oxidation, H_2O_2 degradation, branched chain amino acid catabolism and some unknown functions, and that peroxisomesinseedlings, cotyledons, leavesand roots were differentiated by organ-specific expressed genes.In one of these mutants, apm1, the peroxisomes are long and reduced in number, apparently as a result of inhibition of division. We showed that APM1 encodes DRP3A (dynamin-related protein 3A), and that mutations in APM1/DRP3A also caused aberrant morphology of mitochondria. The transient expression analysis showed that DRP3A is associated with the cytosolicsideofperoxisomes. Thesesfindingsindicate that the same dynamin molecule is involved in peroxisomal and mitochondrialdivision in higherplants.From analyses of apm2 and apm4 mutants which are difectiveinproteintransportbyPTS1-dependent pathway, we determined that APM2 and APM4 genes encode PEROXIN13 (PEX13) and PEX12, respectively, and revealed that they are responsible for PTS2-as well as PTS1-dependent protein on the peroxisomal membrane.

通过对整个拟南芥基因组中的过氧化物酶体基因的全面调查，我们发现高等植物细胞中的过氧化物酶体的功能有所不同，它们包括迄今为止报道的过氧化物酶体酶的所有基因。它们中的大多数在过氧化物酶体中编码功能未知的蛋白质，对基因表达谱的分析表明，过氧化物酶体分化是由在特定器官中诱导的特定基因的表达引起的。聚类分析表明过氧化物酶体的基本功能是β-氧化、H_2O_2降解、支链氨基酸分解代谢和一些未知功能,并且幼苗、子叶、叶和根中的过氧化物酶体是通过器官特异性表达基因来区分的。这些突变体，apm1，过氧化物酶体很长并且数量减少，显然是由于分裂的抑制。 APM1编码DRP3A（动力相关蛋白3A），APM1/DRP3A的突变也导致线粒体形态异常。瞬时表达分析表明，DRP3A与过氧化物酶体的胞质相关，这些发现表明相同的动力分子参与过氧化物酶体和线粒体的分裂。对高等植物中的 apm2 和 apm4 突变体进行分析通过PTS1依赖性途径影响蛋白质运输，我们确定APM2和APM4基因分别编码PEROXIN13（PEX13）和PEX12，并揭示它们负责过氧化物酶体膜上的PTS2和PTS1依赖性蛋白质。