Document Detail

In vivo and in vitro phosphorylation of the T lymphocyte type n (Kv1.3) potassium channel.
MedLine Citation:
PMID:  8226897     Owner:  NLM     Status:  MEDLINE    
The major species of voltage-gated potassium channel found on mammalian T lymphocytes is referred to as the type n channel. This potassium channel exhibits unique functional properties which distinguish it from other species of potassium channels, including a potential role in the onset of cellular events associated with T cell activation. As a first step in characterizing specific biochemical properties of the type n channel, we have generated polyclonal antisera against bacterial fusion proteins containing peptide regions unique to the mouse and human type n channel. From membranes of T cell lines derived from both mouse (SAK 8 cell line) and human (Jurkat cell line), the type n channel can be immunoprecipitated following either surface labeling with 125I or metabolic labeling with 32P. The apparent molecular mass of the immunoprecipitated type n channel is approximately 65 kDa, significantly greater than that of the 58-kDa in vitro translated product, and suggestive of post-translational modification events. Phosphoamino acid analysis of the metabolically labeled Jurkat type n channel reveals phosphorylation of serine residues exclusively. In vitro studies also describe the ability of both protein kinase A and protein kinase C to phosphorylate the Jurkat type n channel. The former kinase also appears to phosphorylate a 40-kDa protein which co-immunoprecipitates with the type n channel. These data suggest that direct phosphorylation of the T lymphocyte type n potassium channel or its associated 40-kDa subunit may serve as a means by which channel activity is regulated.
Y C Cai; J Douglass
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Publication Detail:
Type:  Comparative Study; In Vitro; Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The Journal of biological chemistry     Volume:  268     ISSN:  0021-9258     ISO Abbreviation:  J. Biol. Chem.     Publication Date:  1993 Nov 
Date Detail:
Created Date:  1993-11-29     Completed Date:  1993-11-29     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  2985121R     Medline TA:  J Biol Chem     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  23720-7     Citation Subset:  IM    
Vollum Institute, Oregon Health Sciences University, Portland 97201.
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MeSH Terms
Amino Acid Sequence
Cell Line
Cell Membrane
Cyclic AMP-Dependent Protein Kinases / metabolism
Immunologic Techniques
Molecular Sequence Data
Potassium Channels / metabolism*
Precipitin Tests
Protein Kinase C / metabolism
Protein Processing, Post-Translational
Recombinant Fusion Proteins / chemistry,  immunology
Sequence Alignment
Sequence Homology, Amino Acid
T-Lymphocytes / metabolism*
Grant Support
Reg. No./Substance:
0/Potassium Channels; 0/Recombinant Fusion Proteins; EC AMP-Dependent Protein Kinases; EC Kinase C

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