Evidence for a functional interaction between the ClC-2 chloride channel and the retrograde motor dynein complex.
The ClC-2 chloride channel has been implicated in essential physiological functions. Analyses of ClC-2 knock-out mice suggest that ClC-2 expression in retinal pigment epithelia and Sertoli cells normally supports the viability of photoreceptor cells and male germ cells, respectively. Further, other studies suggest that ClC-2 expression in neurons may modify inhibitory synaptic transmission via the gamma-aminobutyric acid, type A receptor. However, complete understanding of the physiological functions of ClC-2 requires elucidation of the molecular basis for its regulation. Using cell imaging and biochemical and electrophysiological techniques, we show that expression of ClC-2 at the cell surface may be regulated via an interaction with the dynein motor complex. Mass spectrometry and Western blot analysis of eluate from a ClC-2 affinity matrix showed that heavy and intermediate chains of dynein bind ClC-2 in vitro. The dynein intermediate chain co-immunoprecipitates with ClC-2 from hippocampal membranes suggesting that they also interact in vivo. Disruption of dynein motor function perturbs ClC-2 localization and increases the functional expression of ClC-2 in the plasma membranes of COS7 cells. Thus, cell surface expression of ClC-2 may be regulated by dynein motor activity. This work is the first to demonstrate an in vivo interaction between an ion channel and the dynein motor complex.
Dhani
Sonja U
SU
Programme in Structural Biology, Research Institute, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 2X8, Canada.
Mohammad-Panah
Raha
R
Ahmed
Najma
N
Ackerley
Cameron
C
Ramjeesingh
Mohabir
M
Bear
Christine E
CE
D000818:Animals; D000090007:CLC-2 Chloride Channels; D019556:COS Cells; D018118:Chloride Channels / Q000032:analysis / Q000502:physiology*; D002712:Chlorides / Q000378:metabolism; D004398:Dyneins / Q000502:physiology*; D011992:Endosomes / Q000378:metabolism; D008297:Male; D008870:Microtubules / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley
D000090007:CLC-2 Chloride Channels; D018118:Chloride Channels; D002712:Chlorides; D004398:Dyneins