geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Cysteine-specific ubiquitination protects the peroxisomal import receptor Pex5p against proteasomal degradation


, : Cysteine-specific ubiquitination protects the peroxisomal import receptor Pex5p against proteasomal degradation. Bioscience Reports 35(3): -

Peroxisomal matrix protein import is mediated by dynamic import receptors, which cycle between the peroxisomal membrane and the cytosol. Proteins with a type 1 peroxisomal targeting signal (PTS1) are bound by the import receptor Pex5p in the cytosol and guided to the peroxisomal membrane. After cargo translocation into the peroxisomal matrix, the receptor is released from the membrane back to the cytosol in an ATP-dependent manner by the AAA-type ATPases Pex1p and Pex6p. These mechanoenzymes recognize ubiquitinated Pex5p-species as substrates for membrane extraction. The PTS1-receptor is either polyubiquitinated via peptide bonds at two certain lysines and results in proteasomal degradation or monoubiquitinated via a thioester-bond at a conserved cysteine, which enables the recycling of Pex5p and further rounds of matrix protein import. To investigate the physiological relevance of the conserved N-terminal cysteine of Pex5p, the known target amino acids for ubiquitination were substituted by site-directed mutagenesis. In contrast with Pex5pC6A, Pex5pC6K turned out to be functional in PTS1 import and utilization of oleic acid, independent of the lysines at position 18 and 24. In contrast with wild-type Pex5p, Pex5pC6K displays an ubiquitination pattern, similar to the polyubiquitination pattern of Pex4p or Pex22p mutant strains. Moreover, Pex5pC6K displays a significantly reduced steady-state level when the deubiquitinating enzyme Ubp15p is missing. Thus, our results indicate that not the cysteine residue but the position of ubiquitination is important for Pex5p function. The presence of the cysteine prevents polyubiquitination and rapid degradation of Pex5p.

US$19.90

PMID: 26182377

DOI: 10.1042/BSR20150103


Other references

Htun, N.Zaw.; Mizoue, N.; Yoshida, S., 2013: Changes in determinants of deforestation and forest degradation in Popa Mountain Park, Central Myanmar. Implementing effective conservation requires an understanding of factors affecting deforestation and forest degradation. Previous studies have investigated factors affecting deforestation, while few studies have examined the determinants of both o...

Ukhina, T.V.; Kubanova, A.A.; Shegai, M.M.; Sergeev, P.V., 1994: Lysosomes of normal and pathologically changed skin. Vestnik Dermatologii i Venerologii 0(4): 28-30

Simbuerger, E.; Plaschke, M.; Fritschy, J.M.; Nitsch, R., 2001: Localization of two major GABAA receptor subunits in the dentate gyrus of the rat and cell type-specific up-regulation following entorhinal cortex lesion. GABA(A) receptor subunits show a specific regional distribution in the CNS during development and in the adult animal. In the hippocampal formation, individual subsets of GABAergic interneurons are highly immunoreactive for the alpha1-subunit, whe...

Knudsen Niels Tvis; Theakstone Wilfred H., 1997: Recent changes of the glaciers of Svartisen and Okstindan, Norway. Aarhus Geoscience: ges 113-128. 1997.

Holland, H.C., 1962: Massed practice and reminiscence as a function of the distribution of trials on the rotating spiral. Life Sciences 1: 405-409

Middleton, M.R.; Thatcher, N.; McMurry, T.Brian.H.; McElhinney, R.Stanley.; Donnelly, D.J.; Margison, G.P., 2002: Effect of O6-(4-bromothenyl)guanine on different temozolomide schedules in a human melanoma xenograft model. The DNA repair protein O(6)-alkylguanine DNA alkyltransferase (ATase) is a major component of resistance to treatment with methylating agents and nitrosoureas. Inactivation of the protein, via the administration of pseudosubstrates, prior to chemo...

Gospodarenko, A.L.; Ardashev, V.N.; Tiurin, V.P.; Chernetsov, V.A.; Iakovlev, V.B.; Vrublevskiĭ, O.Iu.; Makarenko, A.S.; Sokolianskiĭ, N.V.; Chernov, S.A.; Kucherov, V.V.; Davrent'eva, T.A., 1998: Experience with the thrombolytic therapy of myocardial infarct. Voenno-Meditsinskii Zhurnal 318(11): 40-45

Klaus Wilhelm, 1970: Utilization of spores in evaporite studies. Pages 30-33 1970

Veneselli, E., 1991: Electromyographic aspects of metabolic myopathies. Minerva Pediatrica 43(3): 107-110

Rudel, A., 1945: Sur la presence de Ceresa bubalus en Auvergne. Revue des Sciences Naturelles d'Auvergne Clermont-Ferrand (N S): 11: 1-2: 15-17