TY - JOUR
T1 - 70-kDa peroxisomal membrane protein related protein (P70R/ABCD4) localizes to endoplasmic reticulum not peroxisomes, and NH2-terminal hydrophobic property determines the subcellular localization of ABC subfamily D proteins
AU - Kashiwayama, Yoshinori
AU - Seki, Midori
AU - Yasui, Akina
AU - Murasaki, Yoshiyuki
AU - Morita, Masashi
AU - Yamashita, Yukari
AU - Sakaguchi, Masao
AU - Tanaka, Yoshitaka
AU - Imanaka, Tsuneo
N1 - Funding Information:
This research was supported in part by a Grant-in-Aid for the Research on Measures for Intractable Diseases from the Ministry of Health, Labour and Welfare of Japan, and for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan (18590049, 18790050, and 20590054), and the Sasakawa Scientific Research Grant from The Japan Science Society. We would like to thank Pacific Edit for their assistance in editing the manuscript.
PY - 2009/1/15
Y1 - 2009/1/15
N2 - 70-kDa peroxisomal membrane protein related protein (P70R/ABCD4) is a member of ATP-binding cassette (ABC) protein subfamily D. ABC subfamily D proteins are also known as peroxisomal ABC proteins. Therefore, P70R is thought to be a peroxisomal membrane protein. However, the subcellular localization of P70R is not extensively investigated. In this study, we transiently expressed P70R in fusion with HA (P70R-HA) in CHO cells and examined subcellular localization by immunofluorescence. Surprisingly, P70R-HA was localized to the endoplasmic reticulum (ER), not to peroxisomes. To examine the ER-targeting property of P70R, we expressed various NH2-terminal deletion constructs of P70R. Among the NH2-terminal deletion constructs, mutant proteins starting with hydrophobic transmembrane segment (TMS) were localized to ER, but the ones containing the NH2-terminal hydrophilic cytosolic domain were not. ABC subfamily D proteins destined for peroxisomes have NH2-terminal hydrophilic region adjacent to TMS1. However, only P70R lacks the region and is translated with NH2-terminal hydrophobic TMS1. Furthermore, attachment of the NH2-terminal hydrophilic domain to the NH2-terminus of P70R excluded P70R from the ER-targeting pathway. These data suggest that P70R resides in the ER but not the peroxisomal membranes, and the hydrophobic property of NH2-terminal region determines the subcellular localization of ABC subfamily D proteins.
AB - 70-kDa peroxisomal membrane protein related protein (P70R/ABCD4) is a member of ATP-binding cassette (ABC) protein subfamily D. ABC subfamily D proteins are also known as peroxisomal ABC proteins. Therefore, P70R is thought to be a peroxisomal membrane protein. However, the subcellular localization of P70R is not extensively investigated. In this study, we transiently expressed P70R in fusion with HA (P70R-HA) in CHO cells and examined subcellular localization by immunofluorescence. Surprisingly, P70R-HA was localized to the endoplasmic reticulum (ER), not to peroxisomes. To examine the ER-targeting property of P70R, we expressed various NH2-terminal deletion constructs of P70R. Among the NH2-terminal deletion constructs, mutant proteins starting with hydrophobic transmembrane segment (TMS) were localized to ER, but the ones containing the NH2-terminal hydrophilic cytosolic domain were not. ABC subfamily D proteins destined for peroxisomes have NH2-terminal hydrophilic region adjacent to TMS1. However, only P70R lacks the region and is translated with NH2-terminal hydrophobic TMS1. Furthermore, attachment of the NH2-terminal hydrophilic domain to the NH2-terminus of P70R excluded P70R from the ER-targeting pathway. These data suggest that P70R resides in the ER but not the peroxisomal membranes, and the hydrophobic property of NH2-terminal region determines the subcellular localization of ABC subfamily D proteins.
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U2 - 10.1016/j.yexcr.2008.10.031
DO - 10.1016/j.yexcr.2008.10.031
M3 - Article
C2 - 19010322
AN - SCOPUS:57749175975
VL - 315
SP - 190
EP - 205
JO - Experimental Cell Research
JF - Experimental Cell Research
SN - 0014-4827
IS - 2
ER -