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Title: Targeting of OSBP-related protein 3 (ORP3) to endoplasmic reticulum and plasma membrane is controlled by multiple determinants

Abstract

The intracellular targeting determinants of oxysterol binding protein (OSBP)-related protein 3 (ORP3) were studied using a series of truncated and point mutated constructs. The pleckstrin homology (PH) domain of ORP3 binds the phosphoinositide-3-kinase (PI3K) products, PI(3,4)P{sub 2} and PI(3,4,5)P{sub 3}. A functional PH domain and flanking sequences are crucial for the plasma membrane (PM) targeting of ORP3. The endoplasmic reticulum (ER) targeting of ORP3 is regulated the by a FFAT motif (EFFDAxE), which mediates interaction with VAMP-associated protein (VAP)-A. The targeting function of the FFAT motif dominates over that of the PH domain. In addition, the exon 10/11 region modulates interaction of ORP3 with the ER and the nuclear membrane. Analysis of a chimeric ORP3:OSBP protein suggests that ligand binding by the C-terminal domain of OSBP induces allosteric changes that activate the N-terminal targeting modules of ORP3. Notably, over-expression of ORP3 together with VAP-A induces stacked ER membrane structures also known as organized smooth ER (OSER). Moreover, lipid starvation promotes formation of dilated peripheral ER (DPER) structures dependent on the ORP3 protein. Based on the present data, we introduce a model for the inter-relationships of the functional domains of ORP3 in the membrane targeting of the protein.

Authors:
 [1];  [1];  [1];  [2];  [1];  [3]
  1. Department of Molecular Medicine, National Public Health Institute, Biomedicum, P.O. Box 104, FI-00251 Helsinki (Finland)
  2. Department of Biological and Environmental Sciences, Division of Biochemistry, Viikki Biocenter, P.O. Box 56, Viikinkaari 5, FI-00014 University of Helsinki (Finland)
  3. Department of Molecular Medicine, National Public Health Institute, Biomedicum, P.O. Box 104, FI-00251 Helsinki (Finland). E-mail: vesa.olkkonen@ktl.fi
Publication Date:
OSTI Identifier:
20717679
Resource Type:
Journal Article
Resource Relation:
Journal Name: Experimental Cell Research; Journal Volume: 310; Journal Issue: 2; Other Information: DOI: 10.1016/j.yexcr.2005.08.003; PII: S0014-4827(05)00378-2; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; ELECTRON MICROSCOPY; ENDOPLASMIC RETICULUM; LIGANDS; LIPIDS; MEMBRANE PROTEINS; PH VALUE; PHENYLALANINE

Citation Formats

Lehto, Markku, Hynynen, Riikka, Karjalainen, Katja, Kuismanen, Esa, Hyvaerinen, Kati, and Olkkonen, Vesa M. Targeting of OSBP-related protein 3 (ORP3) to endoplasmic reticulum and plasma membrane is controlled by multiple determinants. United States: N. p., 2005. Web. doi:10.1016/j.yexcr.2005.08.003.
Lehto, Markku, Hynynen, Riikka, Karjalainen, Katja, Kuismanen, Esa, Hyvaerinen, Kati, & Olkkonen, Vesa M. Targeting of OSBP-related protein 3 (ORP3) to endoplasmic reticulum and plasma membrane is controlled by multiple determinants. United States. doi:10.1016/j.yexcr.2005.08.003.
Lehto, Markku, Hynynen, Riikka, Karjalainen, Katja, Kuismanen, Esa, Hyvaerinen, Kati, and Olkkonen, Vesa M. Tue . "Targeting of OSBP-related protein 3 (ORP3) to endoplasmic reticulum and plasma membrane is controlled by multiple determinants". United States. doi:10.1016/j.yexcr.2005.08.003.
@article{osti_20717679,
title = {Targeting of OSBP-related protein 3 (ORP3) to endoplasmic reticulum and plasma membrane is controlled by multiple determinants},
author = {Lehto, Markku and Hynynen, Riikka and Karjalainen, Katja and Kuismanen, Esa and Hyvaerinen, Kati and Olkkonen, Vesa M.},
abstractNote = {The intracellular targeting determinants of oxysterol binding protein (OSBP)-related protein 3 (ORP3) were studied using a series of truncated and point mutated constructs. The pleckstrin homology (PH) domain of ORP3 binds the phosphoinositide-3-kinase (PI3K) products, PI(3,4)P{sub 2} and PI(3,4,5)P{sub 3}. A functional PH domain and flanking sequences are crucial for the plasma membrane (PM) targeting of ORP3. The endoplasmic reticulum (ER) targeting of ORP3 is regulated the by a FFAT motif (EFFDAxE), which mediates interaction with VAMP-associated protein (VAP)-A. The targeting function of the FFAT motif dominates over that of the PH domain. In addition, the exon 10/11 region modulates interaction of ORP3 with the ER and the nuclear membrane. Analysis of a chimeric ORP3:OSBP protein suggests that ligand binding by the C-terminal domain of OSBP induces allosteric changes that activate the N-terminal targeting modules of ORP3. Notably, over-expression of ORP3 together with VAP-A induces stacked ER membrane structures also known as organized smooth ER (OSER). Moreover, lipid starvation promotes formation of dilated peripheral ER (DPER) structures dependent on the ORP3 protein. Based on the present data, we introduce a model for the inter-relationships of the functional domains of ORP3 in the membrane targeting of the protein.},
doi = {10.1016/j.yexcr.2005.08.003},
journal = {Experimental Cell Research},
number = 2,
volume = 310,
place = {United States},
year = {Tue Nov 01 00:00:00 EST 2005},
month = {Tue Nov 01 00:00:00 EST 2005}
}