A hydrophobic proline-rich motif is involved in the intracellular targeting of temperature-induced lipocalin
Hernández-Gras, Francesc (Centre de Recerca en Agrigenòmica)
Boronat i Margosa, Albert (Centre de Recerca en Agrigenòmica)

Date:	2015
Abstract:	Temperature-induced lipocalins (TILs) play an essential role in the response of plants to different abiotic stresses. In agreement with their proposed role in protecting membrane lipids, TILs have been reported to be associated to cell membranes. However, TILs show an overall hydrophilic character and do not contain any signal for membrane targeting nor hydrophobic sequences that could represent transmembrane domains. Arabidopsis TIL (AtTIL) is considered the ortholog of human ApoD, a protein known to associate to membranes through a short hydrophobic loop protruding from strands 5 and 6 of the lipocalin β-barrel. An equivalent loop (referred to as HPR motif) is also present between β-strands 5 and 6 of TILs. The HPR motif, which is highly conserved among TIL proteins, extends over as short stretch of eight amino acids and contains four invariant proline residues. Subcellular localization studies have shown that TILs are targeted to a variety of cell membranes and organelles. We have also found that the HPR motif is necessary and sufficient for the intracellular targeting of TILs. Modeling studies suggest that the HPR motif may directly anchor TILs to cell membranes, favoring in this way further contact with the polar group of membrane lipids. However, some particular features of the HPR motif open the possibility that targeting of TILs to cell membranes could be mediated by interaction with other proteins. The functional analysis of the HPR motif unveils the existence of novel mechanisms involved in the intracellular targeting of proteins in plants.
Grants:	Ministerio de Ciencia e Innovación BIO2009-09523 Ministerio de Economía y Competitividad AGL2013-43522-R Ministerio de Ciencia e Innovación CSD2007-00036 Agència de Gestió d'Ajuts Universitaris i de Recerca 2009/SGR-0026
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Lipocalin ; Temperature-induced lipocalin ; Protein targeting ; Membrane ; Arabidopsis ; Tomato
Published in:	Plant molecular biology, Vol. 88, Issue 3 (June 2015) , p. 301-311, ISSN 1573-5028

DOI: 10.1007/s11103-015-0326-x
PMID: 25957952

11 p, 1.4 MB

The record appears in these collections:
Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > CRAG (Centre for Research in Agricultural Genomics)
Articles > Research articles
Articles > Published articles