Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038187 (starvation)
 24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Muscle growth is determined primarily by the balance between protein synthesis and degradation. When rates of protein synthesis are similar between individuals, protein degradation is critical in explaining differences in growth efficiency. Studies in mammals showed that muscle atrophy results from increased protein breakdown, and is associated with activation of the ubiquitin proteasome pathway, including induction of the muscle-specific ubiquitin protein ligase, MuRF1. Animals lacking MuRF1 are resistant to muscle atrophy. In fish, little is known about the role of the proteasome/MuRF pathway in muscle degradation. The objectives of this study were to: 1) clone and characterize MuRF genes in rainbow trout; and 2) determine expression of MuRF genes in association with starvation- and vitellogenesis-induced muscle atrophy in rainbow trout. We have identified full-length cDNA sequences for three MuRF genes (MuRF1, MuRF2, and MuRF3). These genes encode proteins with typical MuRF structural domains, including a RING-finger, a B-box and a Leucine-rich coiled-coil domain. RT-PCR analysis showed that MuRF genes are predominantly expressed in muscle and heart tissues. Real time PCR analysis revealed that expression of all MuRF genes is up-regulated during starvation and MuRF3 is up-regulated in vitellogenesis-associated muscle degradation. These results suggest that MuRF genes have an important role in fish muscle protein degradation. Further studies are warranted to assess the potential use of MuRF genes as tools to monitor fish muscle growth and degradation.
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PMID:Molecular characterization of the MuRF genes in rainbow trout: Potential role in muscle degradation. 2114 12

The selection of proteins destined for degradation by the ubiquitin-proteasome pathway is coordinated by E3 ubiquitin ligases (E3Ub). One group of E3Ubs is described as muscle-specific RING finger (MuRF) molecules. In mammals, these proteins are believed to be central to targetting of muscle proteins for degradation during physiological perturbations such as starvation and inflammatory responses. In fish, the diversity of MuRF sequences is unexplored as is the expression of their mRNAs. In this study, three MuRF1 cDNAs, denoted as MuRF1a, MuRF1b, and MuRF1c, and a single MuRF2 were identified and characterized in Atlantic salmon. The MuRF1 sequences are highly conserved and encode predicted proteins of 349, 350, and 353 amino acids, whereas MuRF2 encodes a longer protein of 462 amino acids. The evolutionary relationship of these sequences with other fish and mammalian molecules shows that MuRF1a and 1b may have arisen from a recent salmonid duplication. The mRNA of MuRFs was expressed in multiple tissues, with highest abundance in white muscle tissue followed by the heart. The expression of MuRFs was modulated after both starvation and immune challenge. Starvation increased expression of all MuRF mRNAs in white muscle, with the greatest increase found in MuRF1a. A proinflammatory stimulation increased expression of MuRF mRNA in muscle and other tissues indicating a role of these proteins in protein degradation during inflammation.
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PMID:Muscle-specific RING finger (MuRF) cDNAs in Atlantic salmon (Salmo salar) and their role as regulators of muscle protein degradation. 2158 61