Internalization of the Kv1.4 potassium channel is suppressed by clustering interactions with PSD-95

被引:93
作者
Jugloff, DGM
Khanna, R
Schlichter, LC
Jones, OT
机构
[1] Univ Toronto, Western Res Inst, Div Cellular & Mol Biol, Hlth Network, Toronto, ON M5T 2S8, Canada
[2] Univ Toronto, Dept Pharmacol, Toronto, ON M5S 1A8, Canada
[3] Univ Toronto, Dept Physiol, Toronto, ON M5S 1A8, Canada
关键词
D O I
10.1074/jbc.275.2.1357
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 contribution of voltage-dependent ion channels to nerve function depends upon their cell-surface distributions. Nevertheless, the mechanisms underlying channel localization are poorly understood. Two phenomena appear particularly important: the clustering of channels by membrane-associated guanylate kinases (MAGUKs), such as PSD-95, and the regional stabilization of cell-surface proteins by differential suppression of endocytosis. Could these phenomena be related? To test this possibility we examined the effect of PSD-95 on the internalization rate of Kv1.4 K+ channels in transfected HEK293 cells using cell-surface biotinylation assays. When expressed alone Kv1.4 was internalized with a half-life of 87 min, but, in the presence of PSD-95, Kv1.4 internalization was completely suppressed. Immunochemistry and electrophysiology showed PSD-95 had little effect on total or cell-surface levels of Kv1.4 or on current amplitude, activation, or inactivation kinetics. Clustering was necessary and sufficient to suppress Kv1.4 internalization since C35S-PSD-95, a mutant reported to bind but not cluster Kv1.4, (confirmed by imaging cells co-expressing a functional, GFP-variant-tagged Kv1.4) restored and, surprisingly, enhanced the rate of Kv1.4 internalization (t(1/2) = 16 min), These data argue PSD-95-mediated clustering suppresses Kv1.4 internalization and suggest a fundamentally new role for PSD-95, and perhaps other MAGUKs, orchestrating the stabilization of channels at the cell-surface.
引用
收藏
页码:1357 / 1364
页数:8
相关论文
共 53 条
[1]  
Aidley DJ., 1996, ION CHANNELS MOL ACT
[2]   SEROTONIN-MEDIATED ENDOCYTOSIS OF APCAM - AN EARLY STEP OF LEARNING-RELATED SYNAPTIC GROWTH IN APLYSIA [J].
BAILEY, CH ;
CHEN, M ;
KELLER, F ;
KANDEL, ER .
SCIENCE, 1992, 256 (5057) :645-649
[3]   LIQUID JUNCTION POTENTIALS AND SMALL-CELL EFFECTS IN PATCH-CLAMP ANALYSIS [J].
BARRY, PH ;
LYNCH, JW .
JOURNAL OF MEMBRANE BIOLOGY, 1991, 121 (02) :101-117
[4]   Distinct structural requirements for clustering and immobilization of K+ channels by PSD-95 [J].
Burke, NA ;
Takimoto, K ;
Li, DQ ;
Han, WP ;
Watkins, SC ;
Levitan, ES .
JOURNAL OF GENERAL PHYSIOLOGY, 1999, 113 (01) :71-80
[5]   TIME-DEPENDENT AND VOLTAGE-DEPENDENT MODULATION OF A KV1.4 CHANNEL BY A BETA-SUBUNIT (KV-BETA-3) CLONED FROM FERRET VENTRICLE [J].
CASTELLINO, RC ;
MORALES, MJ ;
STRAUSS, HC ;
RASMUSSON, RL .
AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY, 1995, 269 (01) :H385-H391
[6]  
CHANDY KG, 1995, HDB RECEPTORS CHANNE, P1
[7]   Binding of the inward rectifier K+ channel Kir 2.3 to PSD-95 is regulated by protein kinase A phosphorylation [J].
Cohen, NA ;
Brenman, JE ;
Snyder, SH ;
Bredt, DS .
NEURON, 1996, 17 (04) :759-767
[8]  
Cooper EC, 1998, J NEUROSCI, V18, P965
[9]   Synaptic targeting of the postsynaptic density protein PSD-95 mediated by lipid and protein motifs [J].
Craven, SE ;
El-Husseini, AE ;
Bredt, DS .
NEURON, 1999, 22 (03) :497-509
[10]   PDZ proteins organize synaptic signaling pathways [J].
Craven, SE ;
Bredt, DS .
CELL, 1998, 93 (04) :495-498