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Sarah Gold

Publications and source records attributed to Sarah Gold.

6 recordsLinked to original sources
PubMed2025

BRD2 bridges TFIID and MOF-H4K16ac-containing nucleosomes to promote transcriptional initiation.

Members of the bromodomain and extraterminal domain (BET) protein family play a central role in transcription by RNA polymerase II (RNA Pol II). Small-molecule inhibitors that block interaction between BET bromodomains and acetylated histones have been developed for disease therapeutics. However, the BET protein BRD4 does not require bromodomains to perform its major transcriptional elongation control, and mechanisms by which other BET proteins regulate RNA Pol II remain insufficiently understood. Addressing the disparity between pan-BET degraders and BRD4-specific depletion, we report that the BET protein BRD2 generally functions to promote transcriptional initiation in a bromodomain-dependent manner at both promoters and enhancers in human cell lines. We demonstrate that BRD2 bromodomains preferentially bind to histone H4 harboring MOF-mediated H4K16ac, while the BRD2 C-terminal domain facilitates recruitment of TFIID. Our studies provide mechanistic insight into distinct roles for BRD2 and BRD4 in transcriptional initiation and elongation control for proper regulation of gene expression.

Humans↗
PubMed2006

Surfactants for CO2.

For some 15 years the attainment of efficient, nonfluorinated CO2-active surfactants has been a Holy Grail for researchers spanning pure and applied chemical sciences. This article tells the story of small-molecule CO2-active surfactants, from the first tentative observations with fluorinated compounds in 1991 up to recently discovered fluorine-free oxygenated amphiphiles.

Journal Article↗
PubMed2006

Electron density matching as a guide to surfactant design.

The effectiveness at reducing interfacial tension between water and different organic solvents was studied, with 14 structurally different dichain sulfosuccinate surfactants. Variations in chemical structure ranged from linear/branched alkyl tail groups, to phenyl-tipped tail units, to partially and fully fluorinated tails. The solvents n-heptane, toluene, and perfluoroheptane were used as example oil phases. Interfacial activity was measured in terms of a reduced interfacial tension scale, R(IFT), based on the value in the presence of surfactants compared to that for the pure solvent-water interface. Overall surfactant chain structure was determined to be the key factor affecting R(IFT). Furthermore, a strong correlation was observed between R(IFT) and the electron density rho(e) of the different surfactants: with any given oil, the most effective surfactants have rho(e) values closest to that for the solvent. For example, phenyl-tipped surfactants were shown to be comparatively more effective at the interface with an aromatic solvent (toluene) than with an aliphatic n-alkane (heptane). Furthermore, fluorination of the tail groups decreased effectiveness at the hydrocarbon/water interface, which was substantially increased at the fluorocarbon/water interface: this too followed the electron density-matching pattern. The importance of chain-tip chemical structure was also noted, with regard to the introduction of phenyl, CF3-, and H-CF2- terminal moieties. For branched alkyl-tailed surfactants, it was found that effectiveness could be linked to an empirical "branching factor". The significance of the electron density matching of organic solvent and surfactant for the prediction of interfacial activities is highlighted, and this concept may prove useful for the future design of new high-efficiency surfactants.

Journal Article↗
PubMed2005

Ionic liquid-in-oil microemulsions.

Phase stability and small-angle neutron scattering (SANS) data show that surfactant-stabilized nanodomains of a typical ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate [bmim][BF4]) may be dispersed by the nonionic surfactant Triton-X100 in cyclohexane. Analyses of these SANS data are consistent with the formation of ionic liquid-in-oil microemulsion droplets.

Journal Article↗
PubMed2005

The alpha(v)beta6 integrin receptor for Foot-and-mouth disease virus is expressed constitutively on the epithelial cells targeted in cattle.

Field strains of Foot-and-mouth disease virus (FMDV) use a number of alpha(v)-integrins as receptors to initiate infection on cultured cells, and integrins are believed to be the receptors used to target epithelial cells in animals. In this study, immunofluorescence confocal microscopy and real-time RT-PCR were used to investigate expression of two of the integrin receptors of FMDV, alpha(v)beta6 and alpha(v)beta3, within various epithelia targeted by this virus in cattle. These studies show that alpha(v)beta6 is expressed constitutively on the surfaces of epithelial cells at sites where infectious lesions occur during a natural infection, but not at sites where lesions are not normally formed. Expression of alpha(v)beta6 protein at these sites showed a good correlation with the relative abundance of beta6 mRNA. In contrast, alpha(v)beta3 protein was only detected at low levels on the vasculature and not on the epithelial cells of any of the tissues investigated. Together, these data suggest that in cattle, alpha(v)beta6, rather than alpha(v)beta3, serves as the major receptor that determines the tropism of FMDV for the epithelia normally targeted by this virus.

Animals↗