scholarly journals Distinct Ubiquitination Cascades Act on the Peroxisomal Targeting Signal Type 2 Co-receptor Pex18p

Traffic ◽  
2013 ◽  
Vol 14 (12) ◽  
pp. 1290-1301 ◽  
Author(s):  
Fouzi El Magraoui ◽  
Rebecca Brinkmeier ◽  
Andreas Schrötter ◽  
Wolfgang Girzalsky ◽  
Thorsten Müller ◽  
...  
2014 ◽  
Vol 34 (15) ◽  
pp. 2917-2928 ◽  
Author(s):  
T. A. Rodrigues ◽  
I. S. Alencastre ◽  
T. Francisco ◽  
P. Brites ◽  
M. Fransen ◽  
...  

2020 ◽  
Vol 167 (5) ◽  
pp. 429-432
Author(s):  
Tsuneo Imanaka ◽  
Kosuke Kawaguchi

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.


2003 ◽  
Vol 14 (2) ◽  
pp. 810-821 ◽  
Author(s):  
Martin Sichting ◽  
Annette Schell-Steven ◽  
Holger Prokisch ◽  
Ralf Erdmann ◽  
Hanspeter Rottensteiner

Recruiting matrix proteins with a peroxisomal targeting signal type 2 (PTS2) to the peroxisomal membrane requires species-specific factors. In Saccharomyces cerevisiae, the PTS2 receptor Pex7p acts in concert with the redundant Pex18p/Pex21p, whereas inYarrowia lipolytica, Pex20p might unite the function of both S. cerevisiae peroxins. Herein, the genome of the filamentous fungus Neurospora crassa was analyzed for peroxin-encoding genes. We identified a set of 18 peroxins that resembles that of Y. lipolytica rather than that ofS. cerevisiae. Interestingly, proteins homologous to both S. cerevisiae Pex7p and Y. lipolytica Pex20p exist in N. crassa. We report on the isolation of these PTS2-specific peroxins and demonstrate thatNcPex20p can substitute for S. cerevisiaePex18p/Pex21p, but not for ScPex7p. Like Pex18p,NcPex20p did not bind PTS2 protein or the docking proteins in the absence of ScPex7p. Rather,NcPex20p was required before docking to form an import-competent complex of cargo-loaded PTS2 receptors.NcPex7p did not functionally replace yeast Pex7p, probably because the N. crassa PTS2 receptor failed to associate with Pex18p/Pex21p. However, once NcPex7p andNcPex20p had been coexpressed, it proved possible to replace yeast Pex7p. Pex20p and Pex18p/Pex21p are therefore true orthologues, both of which are in need of Pex7p for PTS2 protein import.


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

1996 ◽  
Vol 135 (1) ◽  
pp. 85-95 ◽  
Author(s):  
S J Gould ◽  
J E Kalish ◽  
J C Morrell ◽  
J Bjorkman ◽  
A J Urquhart ◽  
...  

Import of newly synthesized PTS1 proteins into the peroxisome requires the PTS1 receptor (Pex5p), a predominantly cytoplasmic protein that cycles between the cytoplasm and peroxisome. We have identified Pex13p, a novel integral peroxisomal membrane from both yeast and humans that binds the PTS1 receptor via a cytoplasmically oriented SH3 domain. Although only a small amount of Pex5p is bound to peroxisomes at steady state (< 5%), loss of Pex13p further reduces the amount of peroxisome-associated Pex5p by approximately 40-fold. Furthermore, loss of Pex13p eliminates import of peroxisomal matrix proteins that contain either the type-1 or type-2 peroxisomal targeting signal but does not affect targeting and insertion of integral peroxisomal membrane proteins. We conclude that Pex13p functions as a docking factor for the predominantly cytoplasmic PTS1 receptor.


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