Peroxisome biogenesis and human peroxisome biogenesis disorders

过氧化物酶体生物发生和人类过氧化物酶体生物发生障碍

基本信息

批准号：
12308033
负责人：
FUJIKI Yukio
金额：
$ 31.9万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12308033/
关键词：
peroxisome peroxisome biogenesis disorders CHO cell mutants peroxins pathogenic genes membrane proteins AAA ATPase family protein-protein interaction 患者解析膜透過装置

项目摘要

1) PEX3 encoding 42-kDa membrane peroxin was cloned by using a peroxisome membrane assembly-defective CHO mutant, ZPG208. Dysfunction of PEX3 was responsible for peroxisome biogenesis disorders (PBDs) such as Zellweger syndrome of complementation group G.2) Of 3 RING peroxins, including Pex2p, Pex10p, and Pex12p, Pex12p RING finger was essential for peroxisome restoring activity but not necessary for targeting to peroxisomes. Pex12p RING finger binds to Pex10p and peroxisome targeting signal 1 (PTS1)-receptor Pex5p.3) We showed that PEX6, the CG4 pathogenic gene, restored peroxisome assembly in CG6 PBD fibroblasts. This patient was compound heterozygous for PEX6 alleles. Accordingly, human PBDs are classified into 12 CGs by merging CG6 with CG4.4) Two isoforms of Pex5p, Pex5pS and 37-amino acid-longer Pex5pL, are expressed in mammals. We found that Pex5pL interacts with the PTS2 receptor Pex7p-PTS2-protein complexes in the cytosol and translocates them to Pex14p. We defined the functio … More nal Pex5p domains interacting with Pex7p, Pex13p, and Pex14p. An N-terminal half Pex5pL comprising amino acid residues at 1-243 bound to Pex7p, Pex13p and Pex14p and was sufficient for restoring the impaired PTS2 import of pex5 cell mutants, whilst the C-terminal tetratricopeptide repeat motifs were required for PTS1-binding. Seven (six in Pex5pS) pentapeptide WxxxF/Y-motifs residing at the N-terminal region were essential for Pex5p interaction with Pex14p and Pex13p. Pex14p and Pex13p formed a complex with PTS1-loaded Pex5p but dissociated in the presence of cargo-unloaded Pex5p, hence implying that PTS cargoes are released from Pex5p at the step downstream of Pex14p and upstream of Pex13p. We reported that Pex7p shows a bimodal distribution between the cytoplasm and peroxisomes in CHO and human cells, implying that Pex7p shuttles between peroxisomes and the cytosol, like Pex5p. Pex7p requires nearly the full length, including all WD motifs, for its function.5) We recently isolated human PEX26 encoding a novel, 34-kDa type II peroxisomal membrane protein, using a CHO cell mutant ZP167. PEX26 expression restored peroxisomal protein import in only the CG8 PBD patient's fibroblasts. This patient possessed a homozygous, inactivating pathogenic point mutation, R98W. Accordingly, we can state that all of pathogenic genes responsible for 12 CGs PBDs have been cloned. Moreover, Pex6p and Pex1p of the AAA ATPase family were co-immunoprecipitated with Pex26p. Together with several lines of morphological evidence, we concluded that Pex26p recruits Pex6p-Pex1p complexes to peroxisomes. Less

1）通过使用组装缺陷的CHO突变体ZPG208来克隆编码42 kDa膜的PEX3。 PEX12P，PEX12P环对过氧化物酶体的恢复至关重要，但必须忘记PEX12P环形手指与CG4病原基因PEX6结合，将过氧化物组恢复在CG6 PBD纤维中。 4）PEX5P，PEX5PS和37-氨基酸较长的PEX5PL的两个同工型，我们发现PEX5PL与PTS2受体PTS2-PTS2-PTS2-PTS2-PTS2-PTS2-PTS2-PTS2-PTS2-PTS2-PTEIN相互作用，并易位M和PEX14P在1-243处的PEX5PL COMINE酸残基与PEX7P IRED PTS2的pex5细胞突变体导入，而C末端tetratricoptide重复基序是PTS1结合的pts1结合。 N末端区域对于PEX13 p是必不可少的，PEX14P和PEX13P与PTS1负载的PEX5P形成，但在货物未载的PEX5P的情况下解离，PTS CARGOES在PEX5P中释放了PEX5P在CHO和人类细胞中显示了细胞质和过氧化物酶体之间的双峰分布，这意味着PEX7P过氧化物酶体和细胞质之间的PEX7P班车（如PEX7P）需要全长，包括所有WD基序。 II使用ACHO细胞突变体ZP167的膜蛋白，在CG8 PBD患者的成纤维细胞中仅恢复过氧化物酶体的蛋白质AAASE与PEX6P-PEX1P复合物一起使用PEX26P