Alternatively Spliced Human TREK-1 Variants Alter TREK-1 Channel Function and Localization
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Authors
Cowles, Chad L.
Wu, Yi-Ying
Barnett, Scott D.
Lee, Michael T.
Burkin, Heather R.
Buxton, Iain L. O.
Issue Date
2015
Type
Article
Language
Keywords
splice variants , labor , myometrium , human myometrial smooth muscle , preterm labor , uterus , electrophysiology , trek-1 , potassium channels
Alternative Title
Abstract
TREK-1, an outward-rectifying potassium channel activated by stretch, is found in the myometrium of pregnant women. Decreased expression of TREK-1 near term suggests that TREK-1 may contribute to uterine quiescence during gestation. Five alternatively spliced TREK-1 variants were identified in the myometrium of mothers who delivered spontaneously preterm (<37 wk), leading to the hypothesis that these TREK-1 variants could interfere with TREK-1 function or expression. To investigate a potential role for these variants, immunofluorescence, cell surface assays, Western blots, and patch clamp were employed to study TREK-1 and TREK-1 variants expressed in HEK293T cells. The results of this study demonstrate that coexpression of TREK-1 with TREK-1 variants alters TREK-1 expression and suppresses channel function. Each variant affected TREK-1 in a disparate manner. In HEK293T cells coexpressing TREK-1 and each variant, TREK-1 membrane expression was diminished with compartmentalization inside the cell. When expressed alone, individual variants displayed channel properties that were significantly decreased compared to full-length TREK-1. In coexpression studies using patch clamp, basal TREK-1 currents were reduced by similar to 64% (4.3 vs. 12.0 pA/pF) on average at 0 mV when coexpressed with each variant. TREK-1 currents that were activated by intracellular acidosis were reduced an average of similar to 77% (21.4 vs. 94.5 pA/pF) at 0 mV when cells were transfected with TREK-1 and any one of the splice variants. These data correlate the presence of TREK-1 variants to reduced TREK-1 activity, suggesting a pathological role for TREK-1 variants in preterm labor.
Description
Citation
Cowles, C. L., Wu, Y.-Y., Barnett, S. D., Lee, M. T., Burkin, H. R., & Buxton, I. L. O. (2015). Alternatively Spliced Human TREK-1 Variants Alter TREK-1 Channel Function and Localization1. Biology of Reproduction, 93(5). doi:10.1095/biolreprod.115.129791
Publisher
License
Creative Commons Attribution-NonCommercial 3.0 Unported
Journal
Volume
Issue
PubMed ID
ISSN
0006-3363