A novel member of the p64 cl- channel family: subcellular
distribution and nephron-segment specific expression .
Edwards, John C.
Department of Medicine, Washington University School of Medicine,
St. Louis, MO
APStracts 5:0209F, 1998.
Several closely related proteins which have been implicated as
chloride channels of intracellular membranes have recently been
described. We here report the molecular cloning and characterization
of a new member of this family from human cells. Based on sequence
similarity, we conclude that this new protein represents the human
version of previously described protein from rat brain named p64H1.
The human version of p64 H1 (huH1) is a 28.7 kD protein which shows
an apparent molecular weight of 31 kD by SDS-PAGE. A single 4.5 kB
message is detected on northern blots which is present in all tissues
probed. The protein is expressed in an intracellular vesicular
pattern in PancI cells which is distinct from the endoplasmic
reticulum, fluid phase endocytic, and transferrin recycling
compartments, but which does colocalize with caveolin. In human
kidney, huH1 is highly expressed in a diffuse pattern in the apical
domain of proximal tubule cells. HuH1 is expressed less abundantly in
a vesicular pattern in glomeruli and distal nephron.
Received 5 August 1998; accepted in final form 13 November 1998.
APS Manuscript Number F192-8.
Article publication pending Am. J. Physiol. (Renal Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 9 December 1998