| Literature DB >> 8106514 |
M A Kaetzel1, H C Chan, W P Dubinsky, J R Dedman, D J Nelson.
Abstract
The cellular function of annexin IV was evaluated by correlating tissue expression, cellular localization, and whole-cell electrophysiology. Immunolocalization and biochemical data demonstrate that annexin IV is concentrated along the apical membranes of many epithelia. Introduction of purified exogenous annexin IV into colonic T84 cells through a patch pipette specifically prevented Ca(2+)-dependent Cl- current activation. Affinity-purified antibody against annexin IV applied in the same manner enhanced the activation. Reduction of the endogenous level of annexin IV with a derivatized oligodeoxynucleotide antisense to annexin IV mRNA lowered the threshold for the Ca(2+)-induced current response, mimicking the enhancement of current activation exerted by anti-annexin IV antibody. The inhibitory effect of annexin IV on Ca(2+)-dependent Cl- conductance represents a novel mechanism by which Ca(2+)-binding proteins modulate membrane channel activity.Entities:
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Year: 1994 PMID： 8106514
Source DB: PubMed Journal: J Biol Chem ISSN： 0021-9258 Impact factor: 5.157