OVERLAPPING MULTISITE DOMAINS OF THE MUSCARINIC CHOLINERGIC HM1 RECEPTOR INVOLVED IN SIGNAL-TRANSDUCTION AND SEQUESTRATION

被引:0
|
作者
MORO, O
SHOCKLEY, MS
LAMEH, J
SADEE, W
机构
[1] UNIV CALIF SAN FRANCISCO,DEPT PHARM,SAN FRANCISCO,CA 94143
[2] UNIV CALIF SAN FRANCISCO,DEPT PHARMACEUT CHEM,SAN FRANCISCO,CA 94143
关键词
D O I
暂无
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
Alanine mutagenesis scanning of the intracellular portion of the human muscarinic cholinergic Hm1 receptor was performed to identify domains mediating agonist induced receptor sequestration. Using these multiple alanine point mutants of Hm1, we had previously identified several receptor domains in the intracellular loops i1-3 that play a role in coupling to phosphatidyl inositol turnover, most notably, a lipophilic residue, Leu-131, in the conserved i2 loop domain DRYXXVXXPL (Moro, O., Lameh, J., Hogger, P, and Sadee, W. (1993) J. Biol. Chem. 268, 6862-6865). We now demonstrate that; alanine substitutions in three of these domains, i.e. middle of the i2 loop and both junctions of the i3 loop, also result in defective sequestration (loss of surface receptor sites accessible to a polar tracer) in transfected human kidney U293 cells. The i2 loop was studied further by single point mutations. The strongest impairment of sequestration occurred with mutant L131A which was also highly defective in phosphatidyl inositol (PI) coupling. Substitution of Leu-131 with several distinct amino acids indicated that a bulky lipophilic residue is required for sequestration in this position, as shown for coupling to PI turnover. Further, the double point mutation, V127A/L131A, almost completely suppressed both sequestration and coupling of Hm1, In the beta(2) adrenoceptor, alanine substitution of the i2 residue Phe-139, equivalent to Leu-131 in Hm1, also resulted in impaired coupling to adenylyl cyclase and sequestration, indicating a general role for this conserved i2 loop residue in both processes. The combined results show that the multi-site domain involved in signal transduction of Hm1 is similar to and overlaps with that involved in sequestration. However, three Hm1 mutants that were moderately deficient in stimulating PI turnover displayed normal sequestration, suggesting distinct mechanisms. We propose that cellular mediators of receptor sequestration are structurally similar or identical to the heterotrimeric G proteins.
引用
收藏
页码:6651 / 6655
页数:5
相关论文
共 50 条
  • [41] ROLE OF THE MU IMMUNOGLOBULIN HEAVY-CHAIN TRANSMEMBRANE AND CYTOPLASMIC DOMAINS IN B-CELL ANTIGEN RECEPTOR EXPRESSION AND SIGNAL-TRANSDUCTION
    BLUM, JH
    STEVENS, TL
    DEFRANCO, AL
    JOURNAL OF BIOLOGICAL CHEMISTRY, 1993, 268 (36) : 27236 - 27245
  • [42] STRUCTURAL DOMAINS OF INTERLEUKIN-2 RECEPTOR-BETA CRITICAL FOR SIGNAL-TRANSDUCTION - KINASE ASSOCIATION AND NUCLEAR COMPLEX-FORMATION
    HOWARD, OMZ
    KIRKEN, RA
    GARCIA, GG
    HACKETT, RH
    FARRAR, WL
    BIOCHEMICAL JOURNAL, 1995, 306 : 217 - 224
  • [43] The androgen receptor and signal-transduction pathways in hormone-refractory prostate cancer. Part 1: modifications to the androgen receptor
    Edwards, J
    Bartlett, JMS
    BJU INTERNATIONAL, 2005, 95 (09) : 1320 - 1326
  • [44] THE CYTOPLASMIC DOMAIN OF THE INTERLEUKIN-1 RECEPTOR IS REQUIRED FOR NUCLEAR FACTOR-KAPPA-B SIGNAL-TRANSDUCTION
    LEUNG, KY
    BETTS, JC
    XU, L
    NABEL, GJ
    JOURNAL OF BIOLOGICAL CHEMISTRY, 1994, 269 (03) : 1579 - 1582
  • [45] LIPID SIGNAL-TRANSDUCTION PATHWAYS IN ANGIOTENSIN-II TYPE-1 RECEPTOR-TRANSFECTED FIBROBLASTS
    WEN, YS
    CABOT, MC
    CLAUSER, E
    BURSTEN, SL
    NADLER, JL
    AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY, 1995, 269 (02): : C435 - C442
  • [46] A CONSERVED NPLFY SEQUENCE CONTRIBUTES TO AGONIST BINDING AND SIGNAL-TRANSDUCTION BUT IS NOT AN INTERNALIZATION SIGNAL FOR THE TYPE-1 ANGIOTENSIN-II RECEPTOR
    HUNYADY, L
    BOR, M
    BAUKAL, AJ
    BALLA, T
    CATT, KJ
    JOURNAL OF BIOLOGICAL CHEMISTRY, 1995, 270 (28) : 16602 - 16609
  • [47] AGE-RELATED IMPAIRMENT IN STRIATAL MUSCARINIC CHOLINERGIC SIGNAL-TRANSDUCTION IS ASSOCIATED WITH REDUCED MEMBRANE BILAYER WIDTH MEASURED BY SMALL-ANGLE X-RAY-DIFFRACTION
    KELLY, JF
    MASON, RP
    DENISOVA, NA
    JOSEPH, JA
    ERAT, S
    ROTH, GS
    BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 1995, 213 (03) : 869 - 874
  • [48] M1 AND M5 MUSCARINIC ACETYLCHOLINE-RECEPTORS EXPRESSED IN CHO CELLS STIMULATE DIFFERENT SIGNAL-TRANSDUCTION PATHWAYS
    ARONSTAM, RS
    MAHON, BL
    CHOI, E
    PUHL, HL
    MOLECULAR BIOLOGY OF THE CELL, 1995, 6 : 1230 - 1230
  • [49] MOLECULAR-CLONING OF PAXILLIN, A FOCAL ADHESION PHOSPHOPROTEIN INVOLVED IN GROWTH-FACTOR RECEPTOR AND ONCOGENE SIGNAL-TRANSDUCTION IN HEMATOPOIETIC-CELLS
    SALGIA, R
    LI, JL
    LO, SH
    BRUNKHORST, B
    KANSAS, GS
    SUN, Y
    PISICK, E
    ERNST, T
    CHEN, LB
    GRIFFIN, JD
    BLOOD, 1994, 84 (10) : A375 - A375
  • [50] Site of action of the general anesthetic propofol in muscarinic M1 receptor-mediated signal transduction
    Murasaki, O
    Kaibara, M
    Nagase, Y
    Mitarai, S
    Doi, Y
    Sumikawa, K
    Taniyama, K
    JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, 2003, 307 (03): : 995 - 1000