Localization of Furin to the trans-Golgi Network and Recycling from the Cell Surface Involves Ser and Tyr Residues within the Cytoplasmic Domain

doi:10.1074/jbc.270.47.28397

Localization of Furin to the trans-Golgi Network and Recycling from the Cell Surface Involves Ser and Tyr Residues within the Cytoplasmic Domain (*)

From the (1)Institute of Applied Biochemistry,
Institute of Basic Medical Sciences, and
(2) Institute of Biological Sciences and Gene Experiment Center, University of Tsukuba, Tsukuba, Ibaraki 305, Japan

^§§ To whom correspondence should be addressed:
Inst. of Biological Sciences, University of Tsukuba, Tsukuba, Ibaraki 305, Japan.
Tel.: 81-298-53-6356; Fax: 81-298-53-6006; kazunaka{at}sakura.cc.tsukuba.ac.jp.

↵^§ Present address: Dept. of Physiological Chemistry, Faculty of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-01, Japan.
↵** Present address: Dept. of Anatomy, Osaka University Medical School, Yamadaoka, Suita, Osaka 565, Japan.

Abstract

Furin is a membrane-associated endoprotease that catalyzes cleavage of precursor proteins at Arg-X-Lys/Arg-Arg sites. Although, at steady state, furin is predominantly found in the trans-Golgi network (TGN), it also cycles between the TGN and the cell surface. Recently, the cytoplasmic tail of furin has been shown to be sufficient for its localization to the TGN. Within the cytoplasmic domain, there are Ser residues, which we now show are sites for phosphorylation by casein kinase II in vitro, and a Tyr-containing sequence, both of which have been shown to be important for other TGN proteins to localize to this compartment. In the present study, we show by site-directed mutagenesis that these residues are important for TGN localization and recycling of furin. Mutation of the Ser residues abrogated the TGN localization. By contrast, mutation of the Tyr residue did not affect the TGN localization but impaired the internalization from the plasma membrane. These observations suggest that distinct cytoplasmic determinants are responsible for retention in the TGN and retrieval from the cell surface of furin.

Footnotes

↵^¶ Recipient of a fellowship from the Japanese Society for the Promotion of Science for Japanese Junior Scientists.
↵* This work was supported in part by grants from the Ministry of Education, Science and Culture of Japan, the Special Research Project on Circulation Biosystem in the University of Tsukuba, the Saneyoshi Scholarship Foundation, the Nissan Science Foundation, the Ciba-Geigy Foundation (Japan) for the Promotion of Science, and Sankyo Co., Ltd. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵⁽⁾ The abbreviations used are:

TGN

trans-Golgi network

MPR

mannose 6-phosphate receptor

CK-II

casein kinase II

PCR

polymerase chain reaction

GST

glutathione S-transferase

MES

4-morpholineethanesulfonic acid.
- Received June 22, 1995.
- Revision received August 31, 1995.