Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have developed a novel method for the expression and purification of p27, the major core protein of simian immunodeficiency virus. Circular dichroism measurements of purified p27 were used to determine the relative amounts of alpha-helix, beta-sheet and unordered secondary structural elements. These empirically determined values appear to be inconsistent with previously published theoretical models based on homology comparisons.
J Mol Biol 1990 Nov 20
PMID:Purification and secondary structure determination of simian immunodeficiency virus p27. 225 20

Prosomes and heat shock protein (HSP) complexes isolated from the cytoplasm of Drosophila cells in culture were biochemically and immunologically characterized. The two complexes were found to separate on sucrose gradients, allowing the analysis of their protein constituents by two-dimensional polyacrylamide gel electrophoresis and by reaction with anti-HSP sera and prosome-specific monoclonal antibodies. All of the prosomal proteins were found to be clearly distinct from the HSP; none of the prosomal proteins was synthesized de novo in heat shock. However, an antiprosome (anti-p27K) monoclonal antibody (mouse anti-duck) recognizing the Drosophila p29K prosomal protein allowed immunoprecipitation from a heat-shocked postmitochondrial supernatant of the crude HSP complex, including the low- and the high-molecular-weight components, in particular the 70 x 10(3)-molecular weight HSP. The highly purified small 16S HSP complex still contained this preexistent p29K prosomal protein, which thus also seems to be a metabolically stable constituent of the HSP complex. The significance of this structural and possibly functional relationship between prosomes and HSP, involving the highly ubiquitous and evolutionarily conserved prosomal protein p27/29K, remains to be elucidated.
Mol Cell Biol 1989 Jun
PMID:Prosomes and heat shock complexes in Drosophila melanogaster cells. 250 9

Immunization of DMBA-treated mice by the glycoprotein fraction from mammary glands of mice BALB/c did not decrease the frequencies of induction of mammary tumors. This is in contrast to the results obtained during immunization by the formaldehyde treated preparation of Mouse Mammary Tumor Virus (MMTV). EcoRI and HindIII cleaved DNA from the DMBA-induced mammary tumors did not contain the additional virus specific fragments. In mammary tumors the expression of p27 MMTV was registered in contrast to normal mammary glands and mammary epithelium cultures in which the proteins of MMTV are not expressed even after induction.
Mol Gen Mikrobiol Virusol 1987 Aug
PMID:[Endogenous MMTV in the normal mammary gland and in dimethylanthracene-induced mammary cancer in BALB/c mice]. 282 5

p21Cip1 is a cyclin-dependent kinase (Cdk) inhibitor that is transcriptionally activated by p53 in response to DNA damage. We have explored the interaction of p21 with the currently known Cdks. p21 effectively inhibits Cdk2, Cdk3, Cdk4, and Cdk6 kinases (Ki 0.5-15 nM) but is much less effective toward Cdc2/cyclin B (Ki approximately 400 nM) and Cdk5/p35 (Ki > 2 microM), and does not associate with Cdk7/cyclin H. Overexpression of P21 arrests cells in G1. Thus, p21 is not a universal inhibitor of Cdks but displays selectivity for G1/S Cdk/cyclin complexes. Association of p21 with Cdks is greatly enhanced by cyclin binding. This property is shared by the structurally related inhibitor p27, suggesting a common biochemical mechanism for inhibition. With respect to Cdk2 and Cdk4 complexes, p27 shares the inhibitory potency of p21 but has slightly different kinase specificities. In normal diploid fibroblasts, the vast majority of active Cdk2 is associated with p21, but this active kinase can be fully inhibited by addition of exogenous p21. Reconstruction experiments using purified components indicate that multiple molecules of p21 can associate with Cdk/cyclin complexes and inactive complexes contain more than one molecule of p21. Together, these data suggest a model whereby p21 functions as an inhibitory buffer whose levels determine the threshold kinase activity required for cell cycle progression.
Mol Biol Cell 1995 Apr
PMID:Inhibition of cyclin-dependent kinases by p21. 762 5

Monoclonal antibodies demonstrated high conservation during evolution of a prosomal protein of M(r) 27,000 and differentiation--specific expression of the epitope. More than 90% of the reacting antigen was found as a p27K protein in the free messenger ribonucleoprotein (mRNP) fraction but another protein of M(r) 38,000, which shared protease fingerprint patterns with the p27K polypeptide, was also labelled in the nuclear and polyribosomal fractions. Sequencing of cDNA recombinant clones encoding the p27/38K protein and comparison with another prosomal protein, p30-33K, demonstrated the existence of a common characteristic sequence pattern containing three highly conserved segments. The genes Hs PROS-27 and Hs PROS-30 were mapped to chromosomes 14 (14q13) and 11 (11p15.1), respectively. The structure of the p27K protein shows multiple potential phosphorylation sites, an NTP-binding fold and an RNA-binding consensus sequence. The Hs PROS-27/beta-galactosidase fusion protein binds a single RNA of about 120 nucleotides from total HeLa cell RNA. Sequence comparisons show that the Hs PROS-27 and Hs PROS-30 genes belong to the gene family that encodes the prosome--MCP (multicatalytic proteinase)--proteasome proteins. Comparison with other members of the family from various species allowed us to show that the tripartite consensus sequence characteristic of the alpha-type sub-family is conserved from archeobacteria to man. The members of this gene family are characterised by very high evolutionary conservation of amino acid sequences of homologous genes and 20%-35% sequence similarity, between different family member within the same species and are clearly distinct from the beta-type family.
Mol Gen Genet 1993 Feb
PMID:The prosomal RNA-binding protein p27K is a member of the alpha-type human prosomal gene family. 768 Nov 38

E.atroseptica 36A cells were transformed by the recombinant plasmids p27-1 and pEA364 (derivatives of the vector plasmid pUC19) containing pectate lyase genes of E.carotovora 17A and E.atroseptica 36A, respectively. The synthesis of pectate lyases determined by the cloned genes of bacteria of both subspecies, as well as the synthesis of the native enzymes, were induced by sodium poly pectate. Increase of the dose of pectate lyase genes did not result in alteration of pectate lyase secretion by E.atroseptica 36ApEA364 cells. At the same time, the efficiency of secretion of heterologous pectate lyases by E.atroseptica 36Ap27-1 cells was lower. The synthesis and secretion of the resident isoenzymes are as efficient as those of the parental cells. The results indicate a high specificity of the pectinase secretory system in Erwinia of different species and, moreover, subspecies.
Mol Gen Mikrobiol Virusol
PMID:[Expression of pectate lyase genes of Erwinia carotovora subsp. carotovora 17A and Erwinia carotovora subsp. atroseptica 36A in Erwinia carotovor substp. atroseptica 36A cells]. 773 92

We have constructed a mycobacterial integrative vector by placing two copies of the insertion sequence IS900 flanking a kanamycin-resistance gene into a 'suicide' vector unable to replicate in mycobacteria. The Mycobacterium leprae gene encoding the M. leprae 18 kDa protein was cloned between the two copies of IS900 to provide expression signals. Constructs were introduced into Mycobacterium species smegmatis, vaccae and bovis BCG by electroporation and selection for kanamycin resistance. The expression of the 18 kDa gene was analysed by Western blotting. Integration of the vector into the M. smegmatis chromosome was analysed by Southern blotting. One to five copies of the vector were detected in each transformant. The SIV gag p27 gene and the foot-and-mouth disease virus VP1 140-160 epitope were successfully cloned into the 18 kDa gene and expression in M. smegmatis was obtained.
Mol Microbiol 1993 Dec
PMID:Construction and use of integrative vectors to express foreign genes in mycobacteria. 793 74

Using an antiserum of a patient with cutaneous manifestations of Lyme borreliosis we have isolated the gene encoding a 27 kDa protein antigen (P27) of Borrelia burgdorferi B29 from a lambda-gt11 expression library. Nucleotide sequence analysis revealed that it is a basic protein of 248 amino acids with a typical prokaryotic leader sequence of 17 amino acid residues at the N-terminus of the proposed translation product. Biochemical investigations showed that P27 is a surface-exposed lipoprotein. From pulsed-field gel electrophoresis and subsequent Southern blot analysis it is evident that the p27 gene is located on a linear plasmid of a size of approximately 55 kb. It was overexpressed in Escherichia coli and the purified recombinant protein was used for biochemical and serological studies. Northern and Western blot analysis demonstrated that p27 is expressed in the European B. burgdorferi strain B29, but not in the American strain B31.
Mol Microbiol 1993 Jun
PMID:Isolation and analysis of a linear plasmid-located gene of Borrelia burgdorferi B29 encoding a 27 kDa surface lipoprotein (P27) and its overexpression in Escherichia coli. 836 56

The cyclin-dependent kinase (CDK) inhibitor p27 binds and inhibits the kinase activity of several CDKs. Here we report an analysis of the behavior and partners of p27 in Swiss 3T3 mouse fibroblasts during normal mitotic cell cycle progression, as well as in cells arrested at different stages in the cycle by growth factor deprivation, lovastatin treatment, or ultraviolet (UV) irradiation. We found that the level of p27 is elevated in cells arrested in G0 by growth factor deprivation or contact inhibition. In G0, p27 was predominantly monomeric, although some portion was associated with residual cyclin A.Cdk2. During G1, all of p27 was associated with cyclin D1.Cdk4 and was then redistributed to cyclin A.Cdk2 as cells entered S phase. The loss of the monomeric p27 pool as cyclins accumulate in G1 is consistent with the in vivo and in vitro data showing that p27 binds better to cyclin.CDK complexes than to monomeric CDKs. In growing cells, the majority of p27 was associated with cyclin D1 and the level of p27 was significantly lower than the level of cyclin D1. In cells arrested in G1 with lovastatin, cyclin D1 was degraded and p27 was redistributed to cyclin A.Cdk2. In contrast to p21 (which is a p27-related CDK inhibitor and is induced by UV irradiation), the level of p27 was reduced after UV irradiation, but because cyclin D1 was degraded more rapidly than p27, there was a transient increase in binding of p27 to cyclin A.Cdk2. These data suggest that cyclin D1.Cdk4 acts as a reservoir for p27, and p27 is redistributed from cyclin D1.Cdk4 to cyclin A.Cdk2 complexes during S phase, or when cells are arrested by growth factor deprivation, lovastatin treatment, or UV irradiation. It is likely that a similar principle of redistribution of p27 is used by the cell in other instances of cell cycle arrest.
Mol Biol Cell 1995 Sep
PMID:Redistribution of the CDK inhibitor p27 between different cyclin.CDK complexes in the mouse fibroblast cell cycle and in cells arrested with lovastatin or ultraviolet irradiation. 853 16

SIVsm chronically infected cultures were obtained after infection of CEMX174 cells with either SIVsmH3 or SIVsmE660. These phenotypically CD4 cells, formed syncytia but only when cocultivated with CD4+ cells. Single cell clones were derived from these cultures and examined for the production of virus-specific proteins. The majority of the clones expressed SIV p27 antigen and low levels of virus reverse transcriptase activity. Western blot analysis, performed with either monoclonal or polyclonal sera, showed that a chronically infected clone (B7) produced particles which contained envelope (gp135 and gp43), gag precursors and gag proteins (p27, p16 and p8). However, these particles (SIVsmB7) lacked detectable levels of vpx and of integrase, and contained several fusion proteins which expressed viral protease antigens. This defective virus failed to infect established CD4+ cell lines, as well as primary cultures of macrophages and of peripheral blood lymphocytes, obtained both from humans and from rhesus macaques. Lack of infection correlated with lack of viral DNA detection by PCR amplification of genomic DNA extracted from these cell cultures. In addition, SIVsmB7 virus lacked infectivity in vivo. Rhesus macaques inoculated with high concentrations of SIVsmB7 showed no viremia and their PBMC were PCR negative. Thus, B7 cells produced stable, non-infectious virus mutants, which contained env and gag proteins, but lacked detectable amounts of vpx and of enzymes required for virus replication. Due to the high constitutive expression of this virus-like particle, we are now testing this preparation as a vaccine.
Cell Mol Biol (Noisy-le-grand) 1995
PMID:Properties of virus-like particles produced by SIV-chronically infected human cell clones. 857 47


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