Year of Publication


Season of Publication


Paper Type

Master's Thesis


College of Arts and Sciences

Degree Name

Master of Science (MS)



NACO controlled Corporate Body

University of North Florida. Department of Biology

First Advisor

Dr. David S. Waddell

Second Advisor

Dr. John D. Hatle

Third Advisor

Dr. Terri N. Ellis

Department Chair

Dr. Cliff Ross

College Dean

Dr. Barbara A. Hetrick


Skeletal muscle atrophy can occur at any age and as a result of numerous physiological conditions and thus, it was necessary to better identify the molecular underpinnings of the atrophy cascade so that new therapeutic targets to treat muscle wasting might be identified. MuRF1 was first identified as a marker of skeletal muscle atrophy over a decade ago; however, recent work suggests that this E3 ubiquitin ligase may participate in muscle wasting by regulating the transcriptional activity of genes differentially expressed in response to muscle atrophy. Dusp4, a dual-specificity phosphatase and member of the MAPK cascade, is induced in response to neurogenic atrophy; however, this induction is significantly blunted in the MuRF1-null mice which are resistant to muscle atrophy. The research presented in this thesis aims to characterize the mechanism by which MuRF1 may transcriptionally regulate Dusp4 and characterizes the function of Dusp4 in skeletal muscle.