Journal article
BKCa channel regulates calcium oscillations induced by alpha-2-macroglobulin in human myometrial smooth muscle cells
Proceedings of the National Academy of Sciences of the United States of America, Vol.113(16), pp.E2335-E2344
04/19/2016
DOI: 10.1073/pnas.1516863113
PMCID: PMC4843459
PMID: 27044074
Abstract
The large-conductance, voltage-gated, calcium (Ca(2+))-activated potassium channel (BKCa) plays an important role in regulating Ca(2+)signaling and is implicated in the maintenance of uterine quiescence during pregnancy. We used immunopurification and mass spectrometry to identify proteins that interact with BKCain myometrium samples from term pregnant (≥37 wk gestation) women. From this screen, we identified alpha-2-macroglobulin (α2M). We then used immunoprecipitation followed by immunoblot and the proximity ligation assay to confirm the interaction between BKCaand both α2M and its receptor, low-density lipoprotein receptor-related protein 1 (LRP1), in cultured primary human myometrial smooth muscle cells (hMSMCs). Single-channel electrophysiological recordings in the cell-attached configuration demonstrated that activated α2M (α2M*) increased the open probability of BKCain an oscillatory pattern in hMSMCs. Furthermore, α2M* caused intracellular levels of Ca(2+)to oscillate in oxytocin-primed hMSMCs. The initiation of oscillations required an interaction between α2M* and LRP1. By using Ca(2+)-free medium and inhibitors of various Ca(2+)signaling pathways, we demonstrated that the oscillations required entry of extracellular Ca(2+)through store-operated Ca(2+)channels. Finally, we found that the specific BKCablocker paxilline inhibited the oscillations, whereas the channel opener NS11021 increased the rate of these oscillations. These data demonstrate that α2M* and LRP1 modulate the BKCachannel in human myometrium and that BKCaand its immunomodulatory interacting partners regulate Ca(2+)dynamics in hMSMCs during pregnancy.
Details
- Title: Subtitle
- BKCa channel regulates calcium oscillations induced by alpha-2-macroglobulin in human myometrial smooth muscle cells
- Creators
- Monali Wakle-Prabagaran - Washington University in St. Louis School of MedicineRamón A Lorca - Washington University in St. Louis School of MedicineXiaofeng Ma - Washington University in St. Louis School of MedicineSusan J Stamnes - University of IowaChinwendu Amazu - Washington University in St. Louis School of MedicineJordy J Hsiao - University of IowaCeleste M Karch - Washington University in St. LouisKrzysztof L Hyrc - Washington University in St. Louis School of MedicineMichael E Wright - University of Iowa, Molecular Physiology and BiophysicsSarah K England - Washington University in St. Louis School of Medicine
- Resource Type
- Journal article
- Publication Details
- Proceedings of the National Academy of Sciences of the United States of America, Vol.113(16), pp.E2335-E2344
- Publisher
- United States
- DOI
- 10.1073/pnas.1516863113
- PMID
- 27044074
- PMCID
- PMC4843459
- ISSN
- 0027-8424
- eISSN
- 1091-6490
- Grant note
- 5R01HD037831 / NICHD NIH HHS K01 AG046374 / NIA NIH HHS R01 HD037831 / NICHD NIH HHS
- Language
- English
- Date published
- 04/19/2016
- Academic Unit
- Molecular Physiology and Biophysics
- Record Identifier
- 9983759100002771
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