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Identification and Characterization of Allograft Inflammatory Factor 1‐Like (Aif1L) in Skeletal Muscle
Author(s) -
Tran Kien,
Waddell David
Publication year - 2016
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.30.1_supplement.1009.14
Subject(s) - downregulation and upregulation , myocyte , skeletal muscle , protein degradation , ubiquitin ligase , microbiology and biotechnology , transfection , green fluorescent protein , muscle atrophy , chemistry , itga7 , biology , fusion protein , ubiquitin , gene , biochemistry , endocrinology , recombinant dna
Skeletal muscle wasting, or atrophy, frequently results from decreased protein synthesis and an associated increase in protein degradation. This shift towards a reduction in protein content of the cell can result from various physiological conditions, including immobilization, denervation, and aging. Muscle RING Finger 1 (MuRF1), an E3 ubiquitin ligase, has been found to be upregulated during almost all conditions of muscle wasting and is believed to play an important role in targeting proteins for degradation. However, preliminary data described in this study provides new evidence that MuRF1 may also act as a transcriptional modulator of atrophy‐induced gene activity, including the regulation of allograft inflammatory factor 1‐like (Aif1L). Aif1L has been identified as a novel skeletal muscle gene that is upregulated in wild‐type mice, while MuRF1‐null mice show blunted upregulation in response to denervation. Aif1L is predicated to contain an EF‐hand domain, which can act as a calcium ion binding domain, and since calcium ions are crucial for proper muscle contraction this gene was investigated further. In order to confirm that Aif1L in expressed in muscle cells, the cDNA of Aif1L was cloned from the C 2 C 12 mouse myoblast cell line and fused with a green fluorescence protein (GFP) tag. C 2 C 12 cells were then transfected with the Aif1L‐GFP expression plasmid in order to localize the Aif1L protein in proliferating myoblast cells. C 2 C 12 cells transiently overexpression Aif1L‐GFP showed punctate fluorescence localized to the perinuclear region of the cytoplasm. The results presented here in combination with additional research into the transcriptional regulation and function of Aif1L will help contribute new insight into the molecular genetic mechanisms of skeletal muscle atrophy and may provide a more complete understanding of how MuRF1 may transcriptionally regulate neurogenic atrophy‐induced gene expression during muscle wasting. Support or Funding Information University of North Florida Transformational Learning Opportunity Grant