Exposed thiols confer localization in the endoplasmic reticulum by retention rather than retrieval

被引:39
作者
Isidoro, C
Maggioni, C
Demoz, M
Pizzagalli, A
Fra, AM
Sitia, R
机构
[1] SAN RAFFAELE SCI INST, DIBIT, I-20132 MILAN, ITALY
[2] UNIV TURIN, DIPARTIMENTO MED & ONCOL SPERIMENTALE, SEZ PATOL GEN, I-10125 TURIN, ITALY
关键词
D O I
10.1074/jbc.271.42.26138
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The cysteine present in the Ig mu chain tailpiece (mu tp) prevents the secretion of unpolymerized IgM intermediates and causes their accumulation in the endoplasmic reticulum (ER). In principle, this can be the consequence of actual retention in this organelle or of retrieval from the Golgi. To determine which of the two mechanisms underlies the cysteine dependent ER localization, we analyze here the post-translational modifications of suitably engineered cathepsin D (CD) molecules. The glycans of this protease are phosphorylated by post-ER phosphotransferases and further modified in the trans-Golgi to generate a mannose 6-phosphate lysosome targeting signal. Only trace amounts of the mu tp-tagged CD (CDM mu tpCys) are phosphorylated, unless retention is reversed by exogenous reducing agents or the critical cysteine mutated (CDM mu tpSer). In contrast, a KDEL-tagged CD, that is retrieved from the Golgi into the ER, acquires phosphates, though mainly resistant to alkaline phosphatase. Similarly to CDM mu tpSer, the few CDM mu tpCys molecules that escape retention and acquire phosphates in the cis-Golgi are transported beyond the KDEL retrieval compartment, as indicated by their sensitivity to alkaline phosphatase. These results demonstrate that the thiol-dependent ER localization arises primarily from true retention, without recycling through the Golgi.
引用
收藏
页码:26138 / 26142
页数:5
相关论文
共 44 条
  • [1] SECRETION OF IMMUNOGLOBULIN-M ASSEMBLY INTERMEDIATES IN THE PRESENCE OF REDUCING AGENTS
    ALBERINI, CM
    BET, P
    MILSTEIN, C
    SITIA, R
    [J]. NATURE, 1990, 347 (6292) : 485 - 487
  • [2] VESICULAR STOMATITIS-VIRUS GLYCOPROTEIN IS SORTED AND CONCENTRATED DURING EXPORT FROM THE ENDOPLASMIC-RETICULUM
    BALCH, WE
    MCCAFFERY, JM
    PLUTNER, H
    FARQUHAR, MG
    [J]. CELL, 1994, 76 (05) : 841 - 852
  • [3] GENERATION OF A LYSOSOMAL-ENZYME TARGETING SIGNAL IN THE SECRETORY PROTEIN PEPSINOGEN
    BARANSKI, TJ
    FAUST, PL
    KORNFELD, S
    [J]. CELL, 1990, 63 (02) : 281 - 291
  • [4] COPI- and COPII-coated vesicles bud directly from the endoplasmic reticulum in yeast
    Bednarek, SY
    Ravazzola, M
    Hosobuchi, M
    Amherdt, M
    Perrelet, A
    Schekman, R
    Orci, L
    [J]. CELL, 1995, 83 (07) : 1183 - 1196
  • [5] BONIFACINO J S, 1991, Current Opinion in Cell Biology, V3, P592, DOI 10.1016/0955-0674(91)90028-W
  • [6] IgM polymerization inhibits the Golgi-mediated processing of the mu-chain carboxy-terminal glycans
    Cals, MM
    Guenzi, S
    Carelli, S
    Simmen, T
    Sparvoli, A
    Sitia, R
    [J]. MOLECULAR IMMUNOLOGY, 1996, 33 (01) : 15 - 24
  • [7] CANTOR AB, 1992, J BIOL CHEM, V267, P23349
  • [8] HIGH-EFFICIENCY TRANSFORMATION OF MAMMALIAN-CELLS BY PLASMID DNA
    CHEN, C
    OKAYAMA, H
    [J]. MOLECULAR AND CELLULAR BIOLOGY, 1987, 7 (08) : 2745 - 2752
  • [9] ISOLATION OF MONOCLONAL-ANTIBODIES SPECIFIC FOR HUMAN C-MYC PROTO-ONCOGENE PRODUCT
    EVAN, GI
    LEWIS, GK
    RAMSAY, G
    BISHOP, JM
    [J]. MOLECULAR AND CELLULAR BIOLOGY, 1985, 5 (12) : 3610 - 3616
  • [10] LIPOFECTION - A HIGHLY EFFICIENT, LIPID-MEDIATED DNA-TRANSFECTION PROCEDURE
    FELGNER, PL
    GADEK, TR
    HOLM, M
    ROMAN, R
    CHAN, HW
    WENZ, M
    NORTHROP, JP
    RINGOLD, GM
    DANIELSEN, M
    [J]. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1987, 84 (21) : 7413 - 7417