The relative binding affinities of PDZ partners for CFTR:: A biochemical basis for efficient Endocytic recycling

被引:92
作者
Cushing, Patrick R. [1 ]
Fellows, Abigail [1 ]
Villone, Daniel [1 ]
Boisguerin, Prisca [2 ]
Madden, Dean R. [1 ]
机构
[1] Dartmouth Med Sch, Dept Biochem, Hanover, NH 03755 USA
[2] Charite, Inst Med Immunol, Berlin, Germany
关键词
D O I
10.1021/bi8003928
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 cystic fibrosis transmembrane conductance regulator (CFTR) is an epithelial chloride channel mutated in patients with cystic fibrosis. Its expression and functional interactions in the apical membrane are regulated by several PDZ (PSD-95, discs large, zonula occludens-1) proteins, which mediate protein-protein interactions, typically by binding C-terminal recognition motifs. In particular, the CFTR-associated ligand (CAL) limits cell-surface levels of the most common disease-associated mutant Delta F508-CFTR. CAL also mediates degradation of wild-type CFTR, targeting it to lysosomes following endocytosis. Nevertheless, wild-type CFTR survives numerous cycles of uptake and recycling. In doing so, how does it repeatedly avoid CAL-mediated degradation? One mechanism may involve competition between CAL and other PDZ proteins including Na+/H+ exchanger-3 regulatory factors I and 2 (NHERF1 and NHERF2). which functionally stabilize cell-surface CFTR. Thus, to understand the biochemical basis of WT-CFTR persistence, we need to know the relative affinities of these partners. However, no quantitative binding data are available for CAL or the individual NHERF2 PDZ domains, and published estimates for the NHERF1 PDZ domains conflict. Here we demonstrate that the affinity of the CAL PDZ domain for the CFTR C-terminus is much weaker than those of NHERF1 and NHERF2 domains, enabling wild-type CFTR to avoid premature entrapment in the lysosomal pathway. At the same time, CAL's affinity is evidently sufficient to capture and degrade more rapidly cycling mutants, such as Delta F508-CFTR. The relatively weak affinity of the CAL:CFTR interaction may provide a pharmacological window for stabilizing rescued Delta F508-CFTR in patients with cystic fibrosis.
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页码:10084 / 10098
页数:15
相关论文
共 55 条
[1]   An improved method for the synthesis of cellulose membrane-bound peptides with free C termini is useful for PDZ domain binding studies [J].
Boisguerin, P ;
Leben, R ;
Ay, B ;
Radziwill, G ;
Moelling, K ;
Dong, LY ;
Volkmer-Engert, R .
CHEMISTRY & BIOLOGY, 2004, 11 (04) :449-459
[2]   Characterization of a putative phosphorylation switch: Adaptation of SPOT synthesis to analyze PDZ domain regulation mechanisms [J].
Boisguerin, Prisca ;
Ay, Bernhard ;
Radziwill, Gerald ;
Fritz, Rafael D. ;
Moelling, Karin ;
Volkmer, Rudolf .
CHEMBIOCHEM, 2007, 8 (18) :2302-2307
[3]   Airway surface dehydration in cystic fibrosis: Pathogenesis and therapy [J].
Boucher, Richard C. .
ANNUAL REVIEW OF MEDICINE, 2007, 58 :157-170
[4]   A kinase-regulated PDZ-domain interaction controls endocytic sorting of the β2-adrenergic receptor [J].
Cao, TT ;
Deacon, HW ;
Reczek, D ;
Bretscher, A ;
von Zastrow, M .
NATURE, 1999, 401 (6750) :286-290
[5]   Modulation of mature cystic fibrosis transmembrane regulator protein by the PDZ domain protein CAL [J].
Cheng, J ;
Wang, H ;
Guggino, WB .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2004, 279 (03) :1892-1898
[6]   A golgi-associated PDZ domain protein modulates cystic fibrosis transmembrane regulator plasma membrane expression [J].
Cheng, J ;
Moyer, BD ;
Milewski, M ;
Loffing, J ;
Ikeda, M ;
Mickle, JE ;
Cutting, GR ;
Li, M ;
Stanton, BA ;
Guggino, WB .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2002, 277 (05) :3520-3529
[7]   DEFECTIVE INTRACELLULAR-TRANSPORT AND PROCESSING OF CFTR IS THE MOLECULAR-BASIS OF MOST CYSTIC-FIBROSIS [J].
CHENG, SH ;
GREGORY, RJ ;
MARSHALL, J ;
PAUL, S ;
SOUZA, DW ;
WHITE, GA ;
ORIORDAN, CR ;
SMITH, AE .
CELL, 1990, 63 (04) :827-834
[8]   ALTERED CHLORIDE-ION CHANNEL KINETICS ASSOCIATED WITH THE DELTA-F508 CYSTIC-FIBROSIS MUTATION [J].
DALEMANS, W ;
BARBRY, P ;
CHAMPIGNY, G ;
JALLAT, S ;
DOTT, K ;
DREYER, D ;
CRYSTAL, RG ;
PAVIRANI, A ;
LECOCQ, JP ;
LAZDUNSKI, M .
NATURE, 1991, 354 (6354) :526-528
[9]  
Dam J, 2004, METHOD ENZYMOL, V384, P185
[10]   PROCESSING OF MUTANT CYSTIC-FIBROSIS TRANSMEMBRANE CONDUCTANCE REGULATOR IS TEMPERATURE-SENSITIVE [J].
DENNING, GM ;
ANDERSON, MP ;
AMARA, JF ;
MARSHALL, J ;
SMITH, AE ;
WELSH, MJ .
NATURE, 1992, 358 (6389) :761-764