117,315 research outputs found
PKC-dependent phosphorylation of the p97 repressor regulates the transcription of aldolase A L-type promoter
No full textExpression of mouse aldolase A L-type mRNA is negatively modulated by a cis element (AldA-NRE), located within the aldolase A distal promoter (pL). AldA-NRE interacts with a 97-kDa repressor protein (p97), which binds DNA in a cell cycle-dependent manner. We demonstrate that the binding between AldA-NRE and p97 decreases during differentiation of human Caco-2 cells and is inversely correlated with L-type mRNA expression. Phosphorylation of the p97 repressor weakened its DNA binding activity in differentiated Caco-2 cells, while dephosphorylation enhanced the binding in proliferating cells. Stimulation of protein kinase C (PKC) in vivo decreased the binding of p97 to AldA-NRE and stimulated transcription, while inhibition of PKC stimulated p97 binding and downregulated transcription. These findings suggest that PKC is a mediator of the binding and silencing function of the p97/AldA-NRE repressor complex. Copyright (C) 1999 Federation of European Biochemical Societies
Regulation of aldolase a L-type mRNA expression in rodent cell lines during differentiation
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Characterization of a silencer that modulates transcription of the human distal aldolase A promoter
No full textNegative regulation of the mouse aldolase A gene: A cell cycle-dependent DNA binding activity functions as a silencer of gene transcription
No full textThe expression of aldolase A L-type mRNA is increased in growth-arrested mouse NIH3T3 cells and remarkably down-regulated in actively proliferating cells. Treatment of proliferating cells with cycloheximide abolished the down-regulation of L-type mRNA expression, thus indicating that a protein factor acts as repressor in proliferating cells. Transient transfection experiments in NIH3T3 cells showed that a negative regulatory cis-element (NRE) is involved in the modulation of the transcriptional activity of the distal L promoter. The repressor, which is a protein of ~97 kDa, binds the murine aldolase A NRE, revealing a much more intense DNA-protein complex in proliferating NIH3T3 cells than in serum-deprived cells. Mutations in the negative regulatory cis-element showed that the GA-rich motif is required for protein binding and silencer function. We conclude that the expression of L- type mRNA is modulated by the interaction between a cell cycle-dependent DNA- binding protein and the murine aldolase A NRE
Negative regulation of the mouse aldolase A gene: a cell cycle dependent DNA binding activity functions as silencer of gene transcription
No full textNegative regulation of the mouse aldolase A gene: a cell cycle dependent DNA binding activity functions as silencer of gene transcription
No full textEtapas do desenvolvimento de uma formulação pó molhável para o Baculovirus anticarsia: secagem e caracterização da superfície do poliedro.
No full textAs primeiras etapas selecionadas para o estudo de uma formulação pó molhável foram a caracterização de superfície quanto a morfologia (MEV) e carga, e a influencia do método de secagem na dispersibilidade das partículas. O vírus foi obtido de lagartas infectadas (CNPSo) e purificado pelo método de Van der Geest. A dispersão resultante apresenta uma distribuição de tamanho entre 1.6 e 1.9 micra, permanecendo invariável quando a preparação foi armazenada ate 6 meses sob refrigeração. O ponto isoelétrico dos poliedros de NPV de B. anticarsia, determinado a partir de gráfico de mobilidade versus pH e 4,5, sendo que em pHs superiores, as partículas estão carregadas negativamente. As dispersões foram secas por liofilização, spray dryer e estufa (27 C.). O processo de secagem determina o estado de agregação, quando os poliedros são dispersos novamente em água, com tamanho ate 27 micra, difíceis de redispersar, enquanto a secagem por spray dryer resulta em um material pouco aglomerado e facilmente dispersível
PKC-dependent phosphorylation of the p97 repressor regulates the transcription of aldolase A L-type promoter
No full textCell-cycle dependent DNA binding activity modulates the expression of the mouse L-type aldolase a mRNA
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