Premium
CHASM is a Unique Biomarker of Type IIa Muscle Fibers and is Regulated by PKA in vivo
Author(s) -
Wooldridge Anne A,
Akimoto Takayuki,
Neppl Ronald J,
Datto Michael B,
Miller Sara,
Kwon Ashley,
Wang Shiliang,
Perriard JeanClaude,
Thresher Randy J.,
Yan Zhen,
Somlyo Avril,
Haystead Timothy A.J.
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.lb31-d
Subject(s) - in vivo , fiber type , phosphoprotein , endocrinology , chemistry , medicine , soleus muscle , phosphorylation , stimulation , skeletal muscle , microbiology and biotechnology , biology
Type II skeletal muscle (SKM) fibers show remarkable plasticity in their ability to switch phenotype in response to exercise or muscle inactivity. Recent evidence suggests that these adaptive responses are related to specific changes within fiber types, which are regulated by neuronal input, hormones or mechanical activity. CHASM is a newly discovered phosphoprotein expressed in certain smooth muscles and not others. Immunohistological studies of wild type and chasm null mice show that native CHASM is only expressed in Type IIa fibers and absent in other fiber types. In contrast to MHCIIa expression, levels of CHASM do not change in response to exercise. CHASM is localized to the M line and I band regions of Type IIa fibers, and treatment of isolated soleus muscle with norepinephrine or 8Br‐cAMP increased CHASM phosphorylation at S301, suggesting the protein is regulated by PKA in vivo. Our findings show that CHASM is a discrete marker of Type IIa fibers and suggest that the protein is likely to infer unique physiological properties upon these fibers in response to adrenergic stimulation that are not found in other SKM fibers.