title: PEX14 is required for microtubule-based peroxisome motility in human cells.
abstract: We have established a procedure for isolating native peroxisomal membrane protein complexes from cultured human cells. Protein-A-tagged peroxin 14 (PEX14), a central component of the peroxisomal protein translocation machinery was genomically expressed in Flp-In-293 cells and purified from digitonin-solubilized membranes. Size-exclusion chromatography revealed the existence of distinct multimeric PEX14 assemblies at the peroxisomal membrane. Using mass spectrometric analysis, almost all known human peroxins involved in protein import were identified as constituents of the PEX14 complexes. Unexpectedly, tubulin was discovered to be the major PEX14-associated protein, and direct binding of the proteins was demonstrated. Accordingly, peroxisomal remnants in PEX14-deficient cells have lost their ability to move along microtubules. In vivo and in vitro analyses indicate that the physical binding to tubulin is mediated by the conserved N-terminal domain of PEX14. Thus, human PEX14 is a multi-tasking protein that not only facilitates peroxisomal protein import but is also required for peroxisome motility by serving as membrane anchor for microtubules.
authors.affiliation: Institute for Physiological Chemistry, Department of Systems Biology, Faculty of Medicine, Ruhr University of Bochum, 44780 Bochum, Germany.
authors.forename: Pratima
authors.initials: P
authors.lastname: Bharti
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schliebs
authors.forename: Tanja
authors.initials: T
authors.lastname: Schievelbusch
authors.forename: Alexander
authors.initials: A
authors.lastname: Neuhaus
authors.forename: Christine
authors.initials: C
authors.lastname: David
authors.forename: Klaus
authors.initials: K
authors.lastname: Kock
authors.forename: Christian
authors.initials: C
authors.lastname: Herrmann
authors.forename: Helmut E
authors.initials: HE
authors.lastname: Meyer
authors.forename: Sebastian
authors.initials: S
authors.lastname: Wiese
authors.forename: Bettina
authors.initials: B
authors.lastname: Warscheid
authors.forename: Carsten
authors.initials: C
authors.lastname: Theiss
authors.forename: Ralf
authors.initials: R
authors.lastname: Erdmann
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002850:Chromatography, Gel; D006801:Humans; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008870:Microtubules / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020675:Peroxisomes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D021381:Protein Transport; D012097:Repressor Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D013347:Subcellular Fractions / Q000737:chemistry / Q000378:metabolism; D013552:Swine
chemical_list: D008565:Membrane Proteins; C455539:PEX14 protein, human; D012097:Repressor Proteins