Chromatin-mediated transcriptional regulation by the yeast architectural factors NHP6A and NHP6B

AUTOR(ES)

Moreira, José M.A.

FONTE

Oxford University Press

RESUMO

The Saccharomyces cerevisiae NHP6A and NHP6B proteins are chromatin architectural factors, functionally and structurally related to the mammalian high mobility group (HMG)-1 and -2 proteins, a family of non-sequence-specific DNA binding proteins. nhp6a nhp6b mutants have various morphological defects and are defective in the induced expression of several RNA polymerase II-transcribed genes. We found that NHP6A/B proteins are also required for full induction of the yeast CHA1 gene. Importantly, CHA1 basal level expression is increased 10-fold in an nhp6a nhp6b double deletion mutant. Micrococcal nuclease and DNase I analysis of the CHA1 gene in this strain showed an open promoter structure, characteristic of the activated state of this promoter, even under non-inducing conditions. To address the possible function of the NHP6A/B proteins in chromatin-mediated gene regulation, we performed whole-genome transcriptional profiling of a Δnhp6a Δnhp6b yeast strain. Our results suggest that NHP6A/B proteins play an important regulatory role, repressing as well as potentiating expression of genes involved in several cellular processes, and that NHP6A/B control is exerted at the level of the individual gene.

Documentos Relacionados

• High-Mobility-Group Proteins NHP6A and NHP6B Participate in Activation of the RNA Polymerase III SNR6 Gene
• Chromatin-mediated regulation of nucleolar structure and RNA Pol I localization by TOR
• Role for ADA/GCN5 products in antagonizing chromatin-mediated transcriptional repression.
• Cell cycle-dependent regulation of thymidine kinase activity introduced into mouse LMTK- cells by DNA and chromatin-mediated gene transfer.
• NHP6A and NHP6B, which encode HMG1-like proteins, are candidates for downstream components of the yeast SLT2 mitogen-activated protein kinase pathway.