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Membrane topologies of PEX13 and PEX14 provide new insights on the mechanism of protein import into peroxisomes.
- Source :
-
The FEBS journal [FEBS J] 2019 Jan; Vol. 286 (1), pp. 205-222. Date of Electronic Publication: 2018 Nov 28. - Publication Year :
- 2019
-
Abstract
- PEX13 and PEX14 are two core components of the so-called peroxisomal docking/translocation module, the transmembrane hydrophilic channel through which newly synthesized peroxisomal proteins are translocated into the organelle matrix. The two proteins interact with each other and with PEX5, the peroxisomal matrix protein shuttling receptor, through relatively well characterized domains. However, the topologies of these membrane proteins are still poorly defined. Here, we subjected proteoliposomes containing PEX13 or PEX14 and purified rat liver peroxisomes to protease-protection assays and analyzed the protected protein fragments by mass spectrometry, Edman degradation and western blotting using antibodies directed to specific domains of the proteins. Our results indicate that PEX14 is a bona fide intrinsic membrane protein with a N <subscript>in</subscript> -C <subscript>out</subscript> topology, and that PEX13 adopts a N <subscript>out</subscript> -C <subscript>in</subscript> topology, thus exposing its carboxy-terminal Src homology 3 [SH3] domain into the organelle matrix. These results reconcile several enigmatic findings previously reported on PEX13 and PEX14 and provide new insights into the organization of the peroxisomal protein import machinery. ENZYMES: Trypsin, EC3.4.21.4; Proteinase K, EC3.4.21.64; Tobacco etch virus protease, EC3.4.22.44.<br /> (© 2018 Federation of European Biochemical Societies.)
- Subjects :
- Animals
Liposomes metabolism
Male
Membrane Proteins genetics
Protein Transport
Rats
Rats, Wistar
Recombinant Proteins genetics
Repressor Proteins genetics
Cell Membrane metabolism
Membrane Proteins metabolism
Peroxisomes metabolism
Recombinant Proteins metabolism
Repressor Proteins metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1742-4658
- Volume :
- 286
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- The FEBS journal
- Publication Type :
- Academic Journal
- Accession number :
- 30414318
- Full Text :
- https://doi.org/10.1111/febs.14697