Expression Noise Can Generate Heterogeneity in Viability but Does Not Affect Cell-to-Cell Epigenetic Silencing of Subtelomeric in Yeast.

Chromatin structure clearly modulates gene expression noise, but the reverse influence has never been investigated, namely how the cell-to-cell expression heterogeneity of chromatin modifiers may generate variable rates of epigenetic modification. Sir2 is a well-characterized histone deacetylase of the Sirtuin family. It strongly influences chromatin silencing, especially at telomeres, subtelomeres and rDNA.

Comparison of the moonlighting actions of the two highly homologous chaperonin 60 proteins of Mycobacterium tuberculosis.

Evidence is emerging that the two chaperonin (Cpn) 60 proteins of Mycobacterium tuberculosis, Cpn60.1 and Cpn60.2, have moonlighting actions that may contribute to the pathology of tuberculosis.

Foamy macrophages from tuberculous patients' granulomas constitute a nutrient-rich reservoir for M. tuberculosis persistence.

Tuberculosis (TB) is characterized by a tight interplay between Mycobacterium tuberculosis and host cells within granulomas. These cellular aggregates restrict bacterial spreading, but do not kill all the bacilli, which can persist for years. In-depth investigation of M.

Langhans giant cells from M. tuberculosis-induced human granulomas cannot mediate mycobacterial uptake.

Tuberculosis is characterized by a tight interplay between Mycobacterium tuberculosis (M. tb) and host cells within granulomas. These cellular aggregates restrain M.

An in vitro dual model of mycobacterial granulomas to investigate the molecular interactions between mycobacteria and human host cells.

In the majority of individuals infected with Mycobacterium tuberculosis, the bacilli cause a long-term asymptomatic infection called latent tuberculosis, a state during which the bacilli reside within granulomas. Latently infected individuals have around 10% risk of progression to clinical disease at a later stage. Determining the state of the mycobacteria and the host cells during this latent phase, i.

Transforming growth factor beta (TGF-beta) potentiates the inhibitory effect of retinoic acid on human breast carcinoma (MCF-7) cell proliferation.

Anchorage-dependent and -independent MCF-7 cell growth was dose-dependently inhibited by retinoic acid (RA) but was insensitive to TGF-beta (from 1 to 100 pM). Growth of MCF-7 monolayer cultures was inhibited (50%) when exposed to 10(-6) M RA. RA was unable to completely inhibit MCF-7 cell proliferation, as concentrations above 10(-6) M were rapidly cytotoxic.

Binding of dynorphin A and related peptides to kappa- and mu-opioid receptors: sensitivity to Na+ ions and Gpp(NH)p.

We have examined the effects of Na+ ions and 5'-guanylyl imidodiphosphate (Gpp(NH)p) on the equilibrium binding of dynorphin A and of a series of related agonist and antagonist peptides to kappa- and mu-opioid receptors in guinea pig (kappa) and rabbit (mu) cerebellum membrane preparations. The binding to kappa sites of dynorphin A and of the peptides displaying agonist properties was strongly inhibited in the presence of 120 mM NaCl and 50 microM Gpp(NH)p. In contrast, a somewhat lower sensitivity to the inhibitory effect of the two allosteric effectors was observed for the analogues of the series showing antagonist properties.

N,N-diallyl-tyrosyl substitution confers antagonist properties on the kappa-selective opioid peptide [D-Pro10]dynorphin A(1-11).

1. In the search for kappa-opioid antagonists, we have designed two N,N-diallyl substituted analogues of the kappa-selective peptide [D-Pro10]dynorphin A (1-11)(DPDYN). In this study, we have examined (i) the binding properties of N,N-diallyl-DPDYN (analogue 1) and N,N-diallyl-[Aib2,3]DPDYN (analogue 2) at the three main types (mu, delta, kappa) of opioid binding sites, (ii) their binding sensitivity to Na+ ions (120 mM NaCl) and guanine nucleotide (50 microM Gpp(NH)p) at mu- and kappa-binding sites and (iii) their biological activity in two pharmacological bioassays specific for mu- and kappa-(guinea-pig ileum) and kappa-(rabbit vas deferens) opioid receptors.