Disease relevance of RPS27A

• The ubiquitin proteasome system in neurodegenerative diseases: sometimes the chicken, sometimes the egg [1].
• Proteins related to the Nedd4 family of ubiquitin protein ligases interact with the L domain of Rous sarcoma virus and are required for gag budding from cells [2].
• Small ubiquitin-related modifiers: A novel and independent class of autoantigens in primary biliary cirrhosis [3].
• The level of a protein synthesized as the carboxyl-terminal domain of one ubiquitin fusion protein was unchanged by a heat stress [4].
• Recent studies indicate that Pael-R can associate with parkin, a ubiquitin ligase which accumulates in Lewy bodies in dopaminergic neurons and is associated with Parkinson's disease [5].

High impact information on RPS27A

• Ubiquitin-mediated degradation of active Src tyrosine kinase [6].
• The degradation of all three proteins required metabolic energy, did not result in production of cleavage intermediates, and did not involve lysosomes or ubiquitin [7].
• A chicken genomic library was screened to obtain genomic clones for ubiquitin genes [8].
• Addition of actinomycin D before heat shock completely abolished the response of ubiquitin mRNA to the stress [8].
• Ubiquitin is a heat shock protein in chicken embryo fibroblasts [9].

Biological context of RPS27A

• DNA sequence analysis of clone 7 indicated its protein product has amino acid sequences identical to bovine ubiquitin [9].
• We discuss some possible roles for ubiquitin in the heat shock response [9].
• Unexpectedly, the ubiquitin moiety of the Ub-t52 protein showed two amino acid substitutions: serine-20 has been replaced by asparagine and serine-57 by alanine [10].
• Chromatin conjugate protein A24 is cleaved and ubiquitin is lost during chicken erythropoiesis [11].
• The most dramatic effect was seen in the rapid disappearance of the ubiquitinated form of histone H2A, one of the major ubiquitin conjugates in cells in the interphase portion of their growth cycle [4].

Anatomical context of RPS27A

• Multiple ubiquitin C-terminal hydrolases from chick skeletal muscle [12].
• Previously, we isolated an ATP-dependent proteolytic pathway in muscle, liver, and reticulocytes that requires ubiquitin and the enzymes which conjugate ubiquitin to proteins [13].
• Ubiquitin, a small 76-amino acid protein which is highly conserved in eukaryotic cells, occurs in several forms other than the free polypeptide [4].
• Similarly, in HeLa cell extracts aged CaM was degraded at a higher rate, even though it was not conjugated to ubiquitin more rapidly than the native species [14].
• Inasmuch as cleavage of the ubiquitin---histone 2A bond of protein A24 and loss of ubiquitin accompanied transcriptional shutdown during erythropoiesis, the presence of protein A24 and ubiquitin in premature polychromatic erythrocytes may reflect the presence of potentially active and transcribing chromatin structures [11].

Associations of RPS27A with chemical compounds

• The extreme conservatism of ubiquitin evolution also allows the inference that certain synonymous serine codons differing at the first two positions were probably mutated at single steps [15].
• Like other UCHs it was sensitive to inhibition by thiol-blocking agents such as N-ethylmaleimide, and by ubiquitin aldehyde [16].
• Cell suspensions were fractionated on albumin gradients to remove nonlymphoid cells and incubated in vitro with bursopoietin, a specific inducer of B cells, or crude chicken thymus extract, a specific inducer of T cells, or ubiquitin, a nonspecific inducer [17].
• Thus, an important component of muscle proteolysis inhibition by leucine, through the PI3K and PKC, is its ability to suppress transcription of the ubiquitin and proteasome C2 subunit, and degradation of myofibrillar protein [18].
• In chick myotubes, leucine suppressed myofibrillar proteolysis (as measured by N(tau)-methylhistidine release), while also decreasing ubiquitin and proteasome C2 subunit mRNA [18].

Regulatory relationships of RPS27A

• Ubiquitin isolated from testis cell nuclei stimulated histone deacetylase in vitro [19].

Other interactions of RPS27A

• UBP41 also released free ubiquitin from poly-His-tagged di-ubiquitin [20].
• Moreover, overexpression of b-catenin caused degradation of Sox9 via the ubiquitin/26S proteasome pathway [21].
• Both the rate and the extent of ubiquitin-lysozyme conjugation, however, are significantly higher with this modified substrate [22].
• In addition, UCH-1 and UCH-7 could remove ubiquitin that had been ligated covalently by an isopeptide linkage to a ubiquitin (RGA)-alpha NH-peptide, the peptide portion of which consists of the 20 amino acids of the calmodulin binding domain of myosin light chain kinase [12].
• Effect of high mobility group nonhistone proteins HMG-20 (ubiquitin) and HMG-17 on histone deacetylase activity assayed in vitro [19].

Analytical, diagnostic and therapeutic context of RPS27A

• When tested in immunoblotting, both peptide antisera reacted with ubiquitinated H2A but not with unconjugated H2A or with ubiquitin [23].
• We have measured the various forms of ubiquitin in cultures of chicken embryo fibroblasts under normal growth conditions and after treatment with a thermal or chemical stress [4].
• Molecular cloning of a novel ubiquitin-specific protease, UBP41, with isopeptidase activity in chick skeletal muscle [20].
• SDS-PAGE analysis of fractionated density gradients suggests, however, that newly synthesized ubiquitin becomes bound nonselectively to both new and preexisting H2A molecules [24].
• The kinetics of incorporation of nascent H2A and ubiquitin into A24 of transformed chicken lymphocytes (MSB cells) have been examined by peptide mapping, COOH-terminus analysis, density labeling and isopycnic centrifugation of chromosomal proteins [24].

References