Molecular cloning and characterization of a mitogen-activated protein kinase-associated intracellular chloride channel.
ERK7, a member of the mitogen-activated protein kinase family, has a carboxyl-terminal tail that is required for ERK7 activation, cellular localization, and its ability to inhibit DNA synthesis. To identify proteins that interact with ERK7, we utilized a yeast two-hybrid screen with the COOH-terminal tail of ERK7 as bait and isolated the cDNA for a novel protein termed CLIC3. The interaction between CLIC3 and ERK7 in mammalian cells was confirmed by co-immunoprecipitation. CLIC3 has significant homology to human intracellular chloride channels 1 (NCC27/CLIC1) and 2 and bovine kidney chloride channel p64. Like NCC27/CLIC1, CLIC3 is predominantly localized in the nucleus and stimulates chloride conductance when expressed in cells. Taken together, these results suggest that CLIC3 is a new member of the human CLIC family. The observed interaction between CLIC3 and ERK7 is the first demonstration of a stable complex between a protein that activates chloride ion transport and a member of the mitogen-activated protein kinase family of signal transducers. The specific association of CLIC3 with the COOH-terminal tail of ERK7 suggests that CLIC3 may play a role in the regulation of cell growth.
Qian
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Z
Ben May Institute for Cancer Research, University of Chicago, Chicago, Illinois 60637, USA.
Okuhara
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D
Abe
M K
MK
Rosner
M R
MR
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D019556:COS Cells; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002417:Cattle; D002467:Cell Nucleus / Q000737:chemistry / Q000378:metabolism; D002478:Cells, Cultured; D018118:Chloride Channels / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D003001:Cloning, Molecular; D004594:Electrophysiology; D004789:Enzyme Activation; D006801:Humans; D007668:Kidney / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D016415:Sequence Alignment
C117019:CLIC3 protein, human; D018118:Chloride Channels; D017871:Calcium-Calmodulin-Dependent Protein Kinases