Interactions of an Arabidopsis RanBPM homologue with LisH-CTLH domain proteins revealed high conservation of CTLH complexes in eukaryotes

0380982 - ÚEB 2013 RIV GB eng J - Journal Article
Tomaštíková, Eva - Cenklová, Věra - Kohoutová, Lucie - Petrovská, Beáta - Váchová, Lenka - Halada, Petr - Kočárová, Gabriela - Binarová, Pavla
Interactions of an Arabidopsis RanBPM homologue with LisH-CTLH domain proteins revealed high conservation of CTLH complexes in eukaryotes.
BMC Plant Biology. Roč. 12, č. 83 (2012). ISSN 1471-2229. E-ISSN 1471-2229
R&D Projects: GA ČR(CZ) GA204/07/1169; GA ČR GP204/09/P155; GA ČR GAP501/12/2333; GA MŠMT(CZ) LC06034; GA MŠMT LC545; GA AV ČR IAA500200719
Grant - others:GA MŠk(CZ) ED0007/01/01
Program: ED
Institutional research plan: CEZ:AV0Z50380511; CEZ:AV0Z50200510
Keywords : Arabidopsis homologue of RanBPM * CTLH-complex * LisH-CTLH domain proteins
Subject RIV: EB - Genetics ; Molecular Biology
Impact factor: 4.354, year: 2012

Based on sequence similarity, we identified a homologue of the human RanBPM in Arabidopsis thaliana. AtRanBPM protein has highly conserved SPRY, LisH, CTLH and CRA domains. Cell fractionation showed that endogenous AtRanBPM or expressed GFP-AtRanBPM are mainly cytoplasmic proteins with only a minor portion detectable in microsomal fractions. AtRanBPM was identified predominantly in the form of soluble cytoplasmic complexes similar to 230 - 500 kDa in size. Immunopurification of AtRanBPM followed by mass spectrometric analysis identified proteins containing LisH and CRA domains; LisH, CRA, RING-U-box domains and a transducin/WD40 repeats in a complex with AtRanBPM. Homologues of identified proteins are known to be components of the C-terminal to the LisH motif (CTLH) complexes in humans and budding yeast. Microscopic analysis of GFP-AtRanBPM in vivo and immunofluorescence localization of endogenous AtRanBPM protein in cultured cells and seedlings of Arabidopsis showed mainly cytoplasmic and nuclear localization. Absence of colocalization with.-tubulin was consistent with the biochemical data and suggests another than a centrosomal role of the AtRanBPM protein. Conclusion: We showed that as yet uncharacterized Arabidopsis RanBPM protein physically interacts with LisH-CTLH domain-containing proteins. The newly identified high molecular weight cytoplasmic protein complexes of AtRanBPM showed homology with CTLH types of complexes described in mammals and budding yeast. Although the exact functions of the CTLH complexes in scaffolding of protein degradation, in protein interactions and in signalling from the periphery to the cell centre are not yet fully understood, structural conservation of the complexes across eukaryotes suggests their important biological role.
Permanent Link: http://hdl.handle.net/11104/0211561