Modulation of ion transport by direct targeting of protein phosphatase type 1 to the Na-K-Cl cotransporter

被引:106
作者
Darman, RB
Flemmer, A
Forbush, B
机构
[1] Yale Univ, Dept Cellular & Mol Physiol, New Haven, CT 06510 USA
[2] Mt Desert Isl Biol Lab, Salsbury Cove, ME 04672 USA
关键词
D O I
10.1074/jbc.C100368200
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 specificity of major protein phosphatases is conferred via targeting subunits, each of which binds specifically to the phosphatase and targets it to the vicinity of substrate proteins. In the case of protein phosphatase 1 (PP1), an RVXFXD motif on a targeting subunit binds to a cleft in PP1c, the catalytic subunit. Here we report that a substrate of PPI, the Na-K-Cl cotransporter (NKCC1), bears this motif in its N terminus near sites of regulatory phosphorylation and that direct binding of PP1 to NKCC1 is functionally important in determining the set point for intracellular chloride regulation. NKCC1 mutants in which the motif is destroyed or improved exhibit dramatically shifted activation curves because of a change in the rate of cotransporter dephosphorylation. Furthermore, direct interaction of NKCC1 and PP1c observed by coprecipitation of the two proteins is not seen in a mutant lacking the site. This establishes a new paradigm of phosphatase specificity, one in which a substrate protein containing an RVXFXD motif binds directly to PP1c; we propose that this may be a quite general mechanism.
引用
收藏
页码:34359 / 34362
页数:4
相关论文
共 37 条
  • [1] Protein phosphatase 1α is a Ras-activated Bad phosphatase that regulates interleukin-2 deprivation-induced apoptosis
    Ayllón, V
    Martínez, C
    García, A
    Cayla, X
    Rebollo, A
    [J]. EMBO JOURNAL, 2000, 19 (10) : 2237 - 2246
  • [2] Behnke RD, 1998, FASEB J, V12, pA1013
  • [3] Brill S., 1995, B MT DESERT ISL BIOL, V34, P53
  • [4] Identification of protein phosphatase-1-binding proteins by microcystin-biotin affinity chromatography
    Campos, M
    Fadden, P
    Alms, G
    Qian, ZD
    Haystead, TAJ
    [J]. JOURNAL OF BIOLOGICAL CHEMISTRY, 1996, 271 (45) : 28478 - 28484
  • [5] Rapid identification of protein phosphatase 1-binding proteins by mixed peptide sequencing and data base searching - Characterization of a novel holoenzymic form of protein phosphatase 1
    Damer, CK
    Partridge, J
    Pearson, WR
    Haystead, TAJ
    [J]. JOURNAL OF BIOLOGICAL CHEMISTRY, 1998, 273 (38) : 24396 - 24405
  • [6] Structural basis for the recognition of regulatory subunits by the catalytic subunit of protein phosphatase 1
    Egloff, MP
    Johnson, DF
    Moorhead, G
    Cohen, PTW
    Cohen, P
    Barford, D
    [J]. EMBO JOURNAL, 1997, 16 (08) : 1876 - 1887
  • [7] Flemmer AW, 1999, FASEB J, V13, pA399
  • [8] Cloning and functional characterization of a cation-Cl-cotransporter-interacting protein
    Garon, L
    Rousseau, F
    Gagnon, E
    Isenring, P
    [J]. JOURNAL OF BIOLOGICAL CHEMISTRY, 2000, 275 (41) : 32027 - 32036
  • [9] Functional interaction of the K-Cl cotransporter (KCC1) with the Na-K-Cl cotransporter in HEK-293 cells
    Gillen, CM
    Forbush, B
    [J]. AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY, 1999, 276 (02): : C328 - C336
  • [10] 3-DIMENSIONAL STRUCTURE OF THE CATALYTIC SUBUNIT OF PROTEIN SERINE/THREONINE PHOSPHATASE-1
    GOLDBERG, J
    HUANG, HB
    KWON, YG
    GREENGARD, P
    NAIRN, AC
    KURIYAN, J
    [J]. NATURE, 1995, 376 (6543) : 745 - 753