High impact information on PEX6

• Peroxisome fusion depends on the lateral movement of Pex1p, Pex6p, and phosphatidylinositol-4,5-bisphosphate-binding proteins from ECR domains to a detergent-soluble portion of the membrane, followed by their release to the cytosol [1].
• A distinct set of peroxisomal proteins, including two ATPases, Pex1p and Pex6p, as well as phosphoinositide- and GTP-binding proteins, transiently associates with the cytosolic face of ECR domains [1].
• Subsequent fusion of the peroxisomal membranes is independent of both Pex1p and Pex6p [2].
• Peroxisomal membrane fusion requires two AAA family ATPases, Pex1p and Pex6p [2].
• The pas8 mutant is deficient for growth, but not for division or segregation of peroxisomes, or for induction of peroxisomal proteins [3].

Biological context of PEX6

• These results suggest that Pex1p, Pex4p, Pex6p, and Pex22p act late in peroxisomal matrix protein import, after matrix protein translocation [4].
• In addition, this fragment encodes Rpd3, a pleiotropic transcription factor (Vidal and Gaber, 1991), and part of Pas8, a protein essential for the biogenesis of peroxisomes (Voorn-Brouwer et al., 1993) [5].
• An 8.2 kb DNA segment from chromosome XIV carries the RPD3 and PAS8 genes as well as the Saccharomyces cerevisiae homologue of the thiamine-repressed nmt1 gene and a chromosome III-duplicated gene for a putative aryl-alcohol dehydrogenase [5].
• Sequence analysis of the full-length cDNA revealed the presence of an open reading frame encoding a 70-kDa polypeptide that belongs to the tetratricopeptide repeat family and that is homologous to the PAS8 and PAS10 gene products, which are required for the formation of normal peroxisomes in yeast [6].
• We could demonstrate that the N-terminal part of Pex6p contains the binding site for Pex15p and that the two AAA cassettes D1 and D2 of Pex6p have opposite effects on this interaction [7].

Anatomical context of PEX6

• As has been shown previously for P. pastoris pex1, pex6, and pex22 mutant cells, we show here that pex4Delta mutant cells contain peroxisomal membrane protein-containing peroxisomes that import residual amounts of peroxisomal matrix proteins [4].
• Pex15p provides the mechanistic basis for the reversible targeting of Pex6p to peroxisomal membranes [7].
• Fusion of P1 and P2 in vitro requires cytosol and ATP hydrolysis and is inhibited by antibodies to two membrane-associated ATPases of the AAA family, Pex1p and Pex6p [8].

Associations of PEX6 with chemical compounds

• Mutations in Walker A (K778A) and B (D831Q) motifs of D2 abolished growth on oleate and led to a considerable larger fraction of peroxisome bound Pex6p [7].
• Functional peroxisomes are dispensable for efficient meiotic development on acetate medium since homozygous delta pex6 diploids sporulated well and produced mature spores that were resistant to diethyl ether [9].
• Here, we describe the Arabidopsis pex6 mutant, which is resistant to the inhibitory effects of IBA on root elongation and the stimulatory effects of IBA on lateral root formation. pex6 also is sucrose dependent during early seedling development and smaller and more pale green than WT throughout development [10].

Physical interactions of PEX6

• Pex22p and the interacting AAA ATPases Pex1p and Pex6p were also found to act after Pex10p [4].

Other interactions of PEX6

• Furthermore, Pex1p and Pex6p were found to act upstream of Pex4p and Pex22p [4].
• Sequencing analysis of a 15.4 kb fragment of yeast chromosome XIV identifies the RPD3, PAS8 and KRE1 loci, five new open reading frames [11].
• On solid oleate medium, homozygous pex5, delta pex6, and pex7 cells were unable to sporulate efficiently, whereas the wild type was [9].

References