scholarly journals Recognition of Peroxisomal Targeting Signal Type 1 by the Import Receptor Pex5p

2001 ◽  
Vol 276 (18) ◽  
pp. 15034-15041 ◽  
Author(s):  
André T. J. Klein ◽  
Phil Barnett ◽  
Gina Bottger ◽  
Daphne Konings ◽  
Henk F. Tabak ◽  
...  
Keyword(s):  
Peroxisomal Targeting ◽  
Signal Type ◽  
Targeting Signal ◽  
Peroxisomal Targeting Signal ◽  
Import Receptor

scholarly journals Peroxisomal lactate dehydrogenase is generated by translational readthrough in mammals

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Fabian Schueren ◽  
Thomas Lingner ◽  
Rosemol George ◽  
Julia Hofhuis ◽  
Corinna Dickel ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
In Silico ◽  
Stop Codon ◽  
The Other ◽  
Translational Readthrough ◽  
Peroxisomal Targeting ◽  
Signal Type ◽  
Targeting Signal ◽  
Peroxisomal Targeting Signal

Translational readthrough gives rise to low abundance proteins with C-terminal extensions beyond the stop codon. To identify functional translational readthrough, we estimated the readthrough propensity (RTP) of all stop codon contexts of the human genome by a new regression model in silico, identified a nucleotide consensus motif for high RTP by using this model, and analyzed all readthrough extensions in silico with a new predictor for peroxisomal targeting signal type 1 (PTS1). Lactate dehydrogenase B (LDHB) showed the highest combined RTP and PTS1 probability. Experimentally we show that at least 1.6% of the total cellular LDHB is targeted to the peroxisome by a conserved hidden PTS1. The readthrough-extended lactate dehydrogenase subunit LDHBx can also co-import LDHA, the other LDH subunit, into peroxisomes. Peroxisomal LDH is conserved in mammals and likely contributes to redox equivalent regeneration in peroxisomes.

scholarly journals A novel dynein-type AAA+ protein with peroxisomal targeting signal type 2

2020 ◽  
Vol 167 (5) ◽  
pp. 429-432
Author(s):  
Tsuneo Imanaka ◽  
Kosuke Kawaguchi
Keyword(s):  
Mammalian Cells ◽  
Ring Structure ◽  
Family Protein ◽  
Peroxisomal Targeting ◽  
Signal Type ◽  
Targeting Signal ◽  
Aaa Protein ◽  
Peroxisomal Targeting Signal

Abstract Peroxisomal matrix proteins are imported into peroxisomes in a process mediated by peroxisomal targeting signal (PTS) type 1 and 2. The PTS2 proteins are imported into peroxisomes after binding with Pex7p. Niwa et al. (A newly isolated Pex7-binding, atypical PTS2 protein P7BP2 is a novel dynein-type AAA+ protein. J Biochem 2018;164:437–447) identified a novel Pex7p-binding protein in CHO cells and characterized the subcellular distribution and molecular properties of the human homologue, ‘P7BP2’. Interestingly, P7BP2 possesses PTS2 at the NH2 terminal and six putative AAA+ domains. Another group has suggested that the protein also possesses mitochondrial targeting signal at the NH2 terminal. In fact, the P7BP2 expressed in mammalian cells is targeted to both peroxisomes and mitochondria. The purified protein from Sf9 cells is a monomer and has a disc-like ring structure, suggesting that P7BP2 is a novel dynein-type AAA+ family protein. The protein expressed in insect cells exhibits ATPase activity. P7BP2 localizes to peroxisomes and mitochondria, and has a common function related to dynein-type ATPases in both organelles.

scholarly journals Peroxisomal Targeting Signal Receptor Pex5p Interacts with Cargoes and Import Machinery Components in a Spatiotemporally Differentiated Manner: Conserved Pex5p WXXXF/Y Motifs Are Critical for Matrix Protein Import

2002 ◽  
Vol 22 (6) ◽  
pp. 1639-1655 ◽  
Author(s):  
Hidenori Otera ◽  
Kiyoko Setoguchi ◽  
Maho Hamasaki ◽  
Toshitaka Kumashiro ◽  
Nobuhiro Shimizu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Matrix Protein ◽  
Protein Import ◽  
Tetratricopeptide Repeat ◽  
Amino Acid Residues ◽  
Peroxisomal Targeting ◽  
Signal Type ◽  
Targeting Signal ◽  
Peroxisomal Targeting Signal

ABSTRACT Two isoforms of the peroxisomal targeting signal type 1 (PTS1) receptor, termed Pex5pS and (37-amino-acid-longer) Pex5pL, are expressed in mammals. Pex5pL transports PTS1 proteins and Pex7p-PTS2 cargo complexes to the initial Pex5p-docking site, Pex14p, on peroxisome membranes, while Pex5pS translocates only PTS1 cargoes. Here we report functional Pex5p domains responsible for interaction with peroxins Pex7p, Pex13p, and Pex14p. An N-terminal half, such as Pex5pL(1-243), comprising amino acid residues 1 to 243, bound to Pex7p, Pex13p, and Pex14p and was sufficient for restoring the impaired PTS2 import of pex5 cell mutants, while the C-terminal tetratricopeptide repeat motifs were required for PTS1 binding. N-terminal Pex5p possessed multiple Pex14p-binding sites. Alanine-scanning analysis of the highly conserved seven (six in Pex5pS) pentapeptide WXXXF/Y motifs residing at the N-terminal region indicated that these motifs were essential for the interaction of Pex5p with Pex14p and Pex13p. Moreover, mutation of several WXXXF/Y motifs did not affect the PTS import-restoring activity of Pex5p, implying that the binding of Pex14p to all of the WXXXF/Y sites was not a prerequisite for the translocation of Pex5p-cargo complexes. Pex5p bound to Pex13p at the N-terminal part, not to the C-terminal SH3 region, via WXXXF/Y motifs 2 to 4. PTS1 and PTS2 import required the interaction of Pex5p with Pex14p but not with Pex13p, while Pex5p binding to Pex13p was essential for import of catalase with PTS1-like signal KANL. Pex5p recruited PTS1 proteins to Pex14p but not to Pex13p. Pex14p and Pex13p formed a complex with PTS1-loaded Pex5p but dissociated in the presence of cargo-unloaded Pex5p, implying that PTS cargoes are released from Pex5p at a step downstream of Pex14p and upstream of Pex13p. Thus, Pex14p and Pex13p very likely form mutually and temporally distinct subcomplexes involved in peroxisomal matrix protein import.

scholarly journals In SilicoAnalysis ofArabidopsis thalianaPeroxisomal 6-Phosphogluconate Dehydrogenase

Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Álvaro D. Fernández-Fernández ◽  
Francisco J. Corpas
Keyword(s):  
Gene Expression ◽  
In Silico ◽  
Redox Homeostasis ◽  
Affymetrix Microarray ◽  
Phosphogluconate Dehydrogenase ◽  
Peroxisomal Targeting ◽  
Targeting Signal ◽  
Xenobiotic Response ◽  
Peroxisomal Targeting Signal

NADPH, whose regeneration is critical for reductive biosynthesis and detoxification pathways, is an essential component in cell redox homeostasis. Peroxisomes are subcellular organelles with a complex biochemical machinery involved in signaling and stress processes by molecules such as hydrogen peroxide (H2O2) and nitric oxide (NO). NADPH is required by several peroxisomal enzymes involved inβ-oxidation, NO, and glutathione (GSH) generation. Plants have various NADPH-generating dehydrogenases, one of which is 6-phosphogluconate dehydrogenase (6PGDH). Arabidopsis contains three6PGDHgenes that probably are encoded for cytosolic, chloroplastic/mitochondrial, and peroxisomal isozymes, although their specific functions remain largely unknown. This study focuses on thein silicoanalysis of the biochemical characteristics and gene expression of peroxisomal 6PGDH (p6PGDH) with the aim of understanding its potential function in the peroxisomal NADPH-recycling system. The data show that a group of plant 6PGDHs contains an archetypal type 1 peroxisomal targeting signal (PTS), whilein silicogene expression analysis using affymetrix microarray data suggests that Arabidopsis p6PGDH appears to be mainly involved in xenobiotic response, growth, and developmental processes.

Sign in / Sign up

Export Citation Format

Share Document