Evidence for Histone Eviction in trans upon Induction of the Yeast PHO5 Promoter

ABSTRACT The yeast PHO5 promoter is a model system for the role of chromatin in eukaryotic gene regulation. Four positioned nucleosomes in the repressed state give way to an extended DNase I hypersensitive site upon induction. Recently this hypersensitive site was shown to be devoid of histone DNA contacts. This raises the mechanistic question of how histones are removed from the promoter. A displacement in trans or movement in cis, the latter according to the well established nucleosome sliding mechanism, are the major alternatives. In this study, we embedded the PHO5 promoter into the context of a small plasmid which severely restricts the space for nucleosome sliding along the DNA in cis. Such a construct would either preclude the chromatin transition upon induction altogether, were it to occur in cis, or gross changes in chromatin around the plasmid would be the consequence. We observed neither. Instead, promoter opening on the plasmid was indistinguishable from opening at the native chromosomal locus. This makes a sliding mechanism for the chromatin transition at the PHO5 promoter highly unlikely and points to histone eviction in trans.

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Role of chromatin conformation in eukaryotic gene regulation

Hereditas (Beijing) ◽

10.3724/sp.j.1005.2011.01291 ◽

2011 ◽

Vol 33 (12) ◽

pp. 1291-1299 ◽

Cited By ~ 1

Author(s):

He-Yuan QI ◽

Zhao-Jun ZHANG ◽

Ya-Juan LI ◽

Xiang-Dong FANG

Keyword(s):

Gene Regulation ◽

Chromatin Conformation ◽

Eukaryotic Gene ◽

Eukaryotic Gene Regulation

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Role of small nuclear RNAs in eukaryotic gene expression

Essays in Biochemistry ◽

10.1042/bse0540079 ◽

2013 ◽

Vol 54 ◽

pp. 79-90 ◽

Cited By ~ 34

Author(s):

Saba Valadkhan ◽

Lalith S. Gunawardane

Keyword(s):

Gene Expression ◽

Protein Interactions ◽

Rna Stability ◽

Splice Sites ◽

Branch Site ◽

Small Nuclear Rnas ◽

Eukaryotic Gene Expression ◽

Eukaryotic Gene ◽

Rna Biogenesis

Eukaryotic cells contain small, highly abundant, nuclear-localized non-coding RNAs [snRNAs (small nuclear RNAs)] which play important roles in splicing of introns from primary genomic transcripts. Through a combination of RNA–RNA and RNA–protein interactions, two of the snRNPs, U1 and U2, recognize the splice sites and the branch site of introns. A complex remodelling of RNA–RNA and protein-based interactions follows, resulting in the assembly of catalytically competent spliceosomes, in which the snRNAs and their bound proteins play central roles. This process involves formation of extensive base-pairing interactions between U2 and U6, U6 and the 5′ splice site, and U5 and the exonic sequences immediately adjacent to the 5′ and 3′ splice sites. Thus RNA–RNA interactions involving U2, U5 and U6 help position the reacting groups of the first and second steps of splicing. In addition, U6 is also thought to participate in formation of the spliceosomal active site. Furthermore, emerging evidence suggests additional roles for snRNAs in regulation of various aspects of RNA biogenesis, from transcription to polyadenylation and RNA stability. These snRNP-mediated regulatory roles probably serve to ensure the co-ordination of the different processes involved in biogenesis of RNAs and point to the central importance of snRNAs in eukaryotic gene expression.

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Women of One or Many Bonnets?: Quaker Women and the Role of Religion in Trans-Appalachian Settlement

NWSA Journal ◽

10.2979/nws.2003.15.2.27 ◽

2003 ◽

Vol 15 (2) ◽

pp. 27-44 ◽

Cited By ~ 1

Author(s):

Neva Jean Specht

Keyword(s):

In Trans ◽

Role Of Religion ◽

Quaker Women

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Potential Dual Role of West Nile Virus NS2B in Orchestrating NS3 Enzymatic Activity in Viral Replication

Viruses ◽

10.3390/v13020216 ◽

2021 ◽

Vol 13 (2) ◽

pp. 216

Author(s):

Alanna C. Tseng ◽

Vivek R. Nerurkar ◽

Kabi R. Neupane ◽

Helmut Kae ◽

Pakieli H. Kaufusi

Keyword(s):

West Nile Virus ◽

Enzymatic Activity ◽

Nonstructural Protein ◽

Antiviral Drug ◽

West Nile ◽

Biochemical Assays ◽

In Trans ◽

Viral Polyprotein ◽

Ns3 Protease

West Nile virus (WNV) nonstructural protein 3 (NS3) harbors the viral triphosphatase and helicase for viral RNA synthesis and, together with NS2B, constitutes the protease responsible for polyprotein processing. NS3 is a soluble protein, but it is localized to specialized compartments at the rough endoplasmic reticulum (RER), where its enzymatic functions are essential for virus replication. However, the mechanistic details behind the recruitment of NS3 from the cytoplasm to the RER have not yet been fully elucidated. In this study, we employed immunofluorescence and biochemical assays to demonstrate that NS3, when expressed individually and when cleaved from the viral polyprotein, is localized exclusively to the cytoplasm. Furthermore, NS3 appeared to be peripherally recruited to the RER and proteolytically active when NS2B was provided in trans. Thus, we provide evidence for a potential additional role for NS2B in not only serving as the cofactor for the NS3 protease, but also in recruiting NS3 from the cytoplasm to the RER for proper enzymatic activity. Results from our study suggest that targeting the interaction between NS2B and NS3 in disrupting the NS3 ER localization may be an attractive avenue for antiviral drug discovery.

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Society as Cause and Cure: The Norms of Transgender Social Medicine

Culture Medicine and Psychiatry ◽

10.1007/s11013-021-09727-4 ◽

2021 ◽

Author(s):

Ketil Slagstad

Keyword(s):

Social Medicine ◽

Social Aspects ◽

Political Role ◽

Therapeutic Regime ◽

Trans People ◽

The Social ◽

In Trans ◽

The Individual ◽

Oral History Interviews

AbstractThis article analyzes how trans health was negotiated on the margins of psychiatry from the late 1970s and early 1980s. In this period, a new model of medical transition was established for trans people in Norway. Psychiatrists and other medical doctors as well as psychologists and social workers with a special interest and training in social medicine created a new diagnostic and therapeutic regime in which the social aspects of transitioning took center stage. The article situates this regime in a long Norwegian tradition of social medicine, including the important political role of social medicine in the creation of the postwar welfare state and its scope of addressing and changing the societal structures involved in disease. By using archival material, medical records and oral history interviews with former patients and health professionals, I demonstrate how social aspects not only underpinned diagnostic evaluations but were an integral component of the entire therapeutic regime. Sex reassignment became an integrative way of imagining and practicing psychiatry as social medicine. The article specifically unpacks the social element of these diagnostic and therapeutic approaches in trans medicine. Because the locus of intervention and treatment remained the individual, an approach with subversive potential ended up reproducing the norms that caused illness in the first place: “the social” became a conformist tool to help the patient integrate, adjust to and transform the pathology-producing forces of society.

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SATP (YaaH), a succinate–acetate transporter protein in Escherichia coli

Biochemical Journal ◽

10.1042/bj20130412 ◽

2013 ◽

Vol 454 (3) ◽

pp. 585-595 ◽

Cited By ~ 45

Author(s):

Joana Sá-Pessoa ◽

Sandra Paiva ◽

David Ribas ◽

Inês Jesus Silva ◽

Sandra Cristina Viegas ◽

...

Keyword(s):

Escherichia Coli ◽

Acetic Acid ◽

Succinic Acid ◽

Critical Role ◽

Amino Acid Residues ◽

E Coli ◽

Transporter Protein ◽

Affinity Constants ◽

In Trans

In the present paper we describe a new carboxylic acid transporter in Escherichia coli encoded by the gene yaaH. In contrast to what had been described for other YaaH family members, the E. coli transporter is highly specific for acetic acid (a monocarboxylate) and for succinic acid (a dicarboxylate), with affinity constants at pH 6.0 of 1.24±0.13 mM for acetic acid and 1.18±0.10 mM for succinic acid. In glucose-grown cells the ΔyaaH mutant is compromised for the uptake of both labelled acetic and succinic acids. YaaH, together with ActP, described previously as an acetate transporter, affect the use of acetic acid as sole carbon and energy source. Both genes have to be deleted simultaneously to abolish acetate transport. The uptake of acetate and succinate was restored when yaaH was expressed in trans in ΔyaaH ΔactP cells. We also demonstrate the critical role of YaaH amino acid residues Leu131 and Ala164 on the enhanced ability to transport lactate. Owing to its functional role in acetate and succinate uptake we propose its assignment as SatP: the Succinate–Acetate Transporter Protein.

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