Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P62988 (Ubiquitin)
 4,326 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To elucidate the molecular basis of muscle atrophy, we have performed the serial analysis of gene expression (SAGE) method with control and immobilized muscles of 10 rats. The genes that expressed >0.5% in muscle are involved in the following three functions: 1) contraction (troponin I, C and T; myosin light chain 1-3; actin; tropomyosin; and parvalbumin), 2) energy metabolism (cytochrome c oxidase I and III, creatine kinase, glyceraldehyde-3-phosphate-dehydrogenase, phosphoglycerate mutase, ATPase 6, and aldolase A), and 3) housekeeping (lens epithelial protein). Muscle atrophy appears to be caused by changes in mRNA levels of specific regulators of proteolysis, protein synthesis, and contractile apparatus assembling, such as polyubiquitin, elongation factor 2, and nebulin. Immobilization has produced a decrease more than threefold in gene expression of enzymes involved in energy metabolism, especially ATPase, cytochrome c oxidase, NADH dehydrogenase, and protein phosphatase 1. Differential gene expressions of selenoprotein W and uroporphyrinogen decarboxylase, which can be involved in oxidative stress, were also observed. Other genes with various functions, such as cholesterol metabolism and growth factors, were also differentially expressed. Moreover, novel genes regulated by immobilization were discovered. Thus, the current study allows a better understanding of global muscle characteristics and the molecular mechanisms of sedentarity and sarcopenia.
 ...
PMID:Characterization of control and immobilized skeletal muscle: an overview from genetic engineering. 1125 86

The efficiency of RNA interference (RNAi) delivery to L1 through L3 stage worms of the sheep parasitic nematode Trichostrongylus colubriformis was investigated using several techniques. These were: (i) feeding of Escherichia coli expressing double stranded RNA (dsRNA); (ii) soaking of short interfering (synthetic) RNA oligonucleotides (siRNA) or in vitro transcribed dsRNA molecules; and (iii) electroporation of siRNA or in vitro transcribed dsRNA molecules. Ubiquitin and tropomyosin were used as a target gene because they are well conserved genes whose DNA sequences are available for several nematode parasite species. Ubiquitin siRNA or dsRNA delivered by soaking or electroporation inhibited development in T. colubriformis but with feeding as a delivery method, RNAi of ubiquitin was not successful. Feeding was, however, successful with tropomyosin as a target, suggesting that mode of delivery is an important parameter of RNAi. Electroporation is a particularly efficient means of inducing RNA in nematodes with either short dsRNA oligonucleotides or with long in vitro transcribed dsRNA molecules. These methods permit routine delivery of dsRNA for RNAi in T. colubriformis larval stage parasites and should be applicable to moderate to high-throughput screening.
 ...
PMID:Development of methods for RNA interference in the sheep gastrointestinal parasite, Trichostrongylus colubriformis. 1602 50

NGF (nerve growth factor) binding to TrkA (tropomyosin receptor kinase A) induces dimerization, autophosphorylation and internalization of the receptor to signalling vesicles for delivery of differentiation signals. TrkA interacts with p75 receptor through the p62-TRAF-6 (tumour-necrosis-factor-receptor-associated factor 6) complex bridging the two receptors. The atypical protein kinase C is activated and recruited to the receptor complex as well. TrkA is Lys63-polyubiquitinated on Lys485 by the E3 (ubiquitin ligase), TRAF-6, and E2 (ubiquitin-conjugating enzyme), UbcH7. Inhibition of polyubiquitination has been observed to interrupt signalling and internalization. Furthermore, an absence of p62 prevents endosomal localization and signalling. Altogether, these findings reveal Lys63-linked polyubiquitin chains and the shuttling protein p62 co-ordinately regulate TrkA internalization, trafficking and sorting.
 ...
PMID:The role of ubiquitin in neurotrophin receptor signalling and sorting. 1705 91

Gaps in our knowledge exist regarding the degradation of the tropomyosin-regulated kinase A (TrkA) receptor after addition of neurotrophin, nerve growth factor (NGF). TrkA is rapidly and transiently ubiquitinated upon addition of NGF. Here, we demonstrate that the polyubiquitin tag plays a definitive role in receptor sorting. Treatment of PC12 cells with lactacystin prevented NGF-dependent deubiquitination and degradation of TrkA. However, treatment with methylamine, bafilomycin or leupeptin, did not prevent NGF-dependent deubiquitination but blocked the degradation of TrkA. Employing co-immunoprecipitation, biochemical fractionation and confocal microscopy, the kinetics of receptor trafficking post-internalization was observed to occur as a sequel from endosome/multivesicular body, proteasomes, culminating with degradation in the lysosomes. The trafficking of the polyubiquitin-deficient TrkA receptor mutant K485R was impaired and likewise failed to degrade revealing that the receptor escapes degradation. The interaction of TrkA with proteasomes was confirmed by purification and co-immunoprecipitation. We provide evidence that proteasomal deubiquitinating enzymes trim K63-ubiquitin chains from the TrkA receptor prior to its delivery to lysosomes for degradation. Taken together, our results reveal the existence of a novel proteasome-dependent step in receptor degradation.
 ...
PMID:TrkA receptor endolysosomal degradation is both ubiquitin and proteasome dependent. 1841 53