Item Details

title

Cavβ1a in the Nucleus of Muscle Progenitor Cells: Mechanisms, Functions, and Implications

author

Taylor, Jackson Richard

abstract

CaVbeta subunits are traditionally considered constituents of CaV complexes (CaV1or2, CaVbeta;, and CaV alpha2/delta), where they localize at the plasma membrane and serve to regulate channel expression and gating properties. Several recent publications also show CaVbeta subunit localization in the nucleus. This phenomenon has been observed under a variety of conditions (different cell types, β subunit isoforms, co-expressed proteins, etc). However, the exact mechanisms responsible for CaVbeta; subunit nuclear shuttling, as well as a physiological role for this nuclear localization, remain major questions. Here we find that CaVbeta1a enters the nucleus of myoblasts, and knockdown of CaVbeta1a impairs myoblast proliferation in vitro and in vivo. To test if CaVbeta1a may regulate gene expression, we conducted microarray experiments on RNA extracted from wild type, heterozygous, and CaVbeta1 -null mouse primary myoblasts. A large number of gene transcripts were found to be differentially regulated based on the relative amount of CaVbeta1a expression. To identify specific CaVbeta1a target genes, we performed ChIP -on-a-chip experiments to locate which promoter regions CaVbeta1a bound to across the entire mouse genome. Nuclear binding partners of CaVbeta1 were screened using affinity purification of CaVbeta1a-YFP from myoblast nuclear fractions coupled with mass spectrometry. Our results support the idea of CaVbeta subunits acting as transcription factors and regulating gene expression independently from CaV's, and suggest these functions may be particularly important to progenitor cell growth.

subject

calcium

development

muscle

stem cell

transcription

contributor

Delbono, Osvaldo (committee chair)

Oppenheim, Ron W (committee member)

Riddle, David (committee member)

Furdui, Cristina (committee member)

Turner, Christopher P (committee member)

date

2013-06-06T21:19:39Z (accessioned)

2014-06-06T08:30:09Z (available)

2013 (issued)

degree

Neuroscience (discipline)

embargo

2014-06-06 (terms)

identifier

http://hdl.handle.net/10339/38578 (uri)

language

en (iso)

publisher

Wake Forest University

type

Dissertation