Regulating the expression of eEF1A to decipher its non canonical functions in eukaryotic cells

The canonical function of eEF1A is delivery of the aminoacylated tRNA to the A site of the ribosome during protein translation, however, it is also known to be an actin binding protein. As well as this actin binding function, eEF1A has been shown to be involved in other cellular processes such as cell proliferation and apoptosis. It has long been thought that the actin cytoskeleton and protein synthesis are linked and eEF1A has been suggested to be a candidate protein to form this link, though very little is understood about the relationship between its two functions. Overexpression of eEF1A has also been shown to be implicated in many different types of cancers, especially cancers that are metastatic, therefore it is important to further understand how eEF1A can affect both translation and the organisation of the actin cytoskeleton. To this end, we aimed to determine the effects of reduced expression of eEF1A on both translation and its non canonical functions in CHO cells. We have shown that reduced expression of eEF1A in this cell system results in no change in protein synthesis, however results in an increased number of actin stress fibres and other proteins associated with these fibres such as myosin IIA, paxillin and vinculin. Cell motility and attachment are also affected by this reduction in eEF1A protein expression. The organisational and motility phenotypes were found to be specific to eEF1A by transforming the cells with plasmids containing either human eEF1A1 or eEF1A2. Though the mechanisms by which these effects are regulated have not yet been established, this data provides evidence to show that the translation and actin binding functions of eEF1A are independent of each other as well as being suggestive of a role for eEF1A in cell motility as supported by the observation that overexpression of eEF1A protein tends to be associated with the cancer cells that are metastatic.

Regulation of ribosomal RNA expression across the lifespan is fine-tuned by maternal diet before implantation

Cells and organisms respond to nutrient deprivation by decreasing global rates of transcription, translation and DNA replication. To what extent such changes can be reversed is largely unknown. We examined the effect of maternal dietary restriction on RNA synthesis in the offspring. Low protein diet fed either throughout gestation or for the preimplantation period alone reduced cellular RNA content across fetal somatic tissues during challenge and increased it beyond controls in fetal and adult tissues after challenge release. Changes in transcription of ribosomal RNA, the major component of cellular RNA, were responsible for this phenotype as evidenced by matching alterations in RNA polymerase I density and DNA methylation at ribosomal DNA loci. Cellular levels of the ribosomal transcription factor Rrn3 mirrored the rRNA expression pattern. In cell culture experiments, Rrn3 overexpression reduced rDNA methylation and increased rRNA expression; the converse occurred after inhibition of Rrn3 activity. These observations define novel mechanism where poor nutrition before implantation irreversibly alters basal rates of rRNA transcription thereafter in a process mediated by rDNA methylation and Rrn3 factor.

Adversarial interpreting – a forensic linguistic perspective

Interactions with second language speakers in public service contexts in England are normally conducted with the assistance of one interpreter. Even in situations where team interpreting would be advisable, for example in lengthy courtroom proceedings, financial considerations mean only one interpreter is normally booked. On occasion, however, more than one interpreter, or an individual (or individuals) with knowledge of the languages in question, may be simultaneously present during an interpreted interaction, either monitoring it or indeed volunteering unsolicited input. During police interviews or trials in England this may happen when the interpreter secured by the defence team to interpret during private consultation with the suspect or defendant is present also in the interview room or the courtroom but two independently sourced interpreters need not be limited to legal contexts. In healthcare settings for example, service users sometimes bring friends or relatives along to help them communicate with service providers only to find that the latter have booked an interpreter as a matter of procedure. By analogy to the nature of the English legal system, I refer to contexts where an interpreter’s output is monitored and/or challenged, either during the speech event or subsequently, as ‘adversarial interpreting’. This conceptualisation reflects the fact that interpreters in such encounters are sourced independently, often by opposing parties, and as a result can rarely be considered a team. My main concern in this paper is to throw spotlight on adversarial interpreting as a hitherto rarely discussed problem in its own right. That it is not an anomaly is evidenced by the many cases around the world where the officially recorded interpreted output was challenged, as mentioned in for example Berk-Seligson (2002), Hayes and Hale (2010), and Phelan (2011). This paper reports on the second stage of a research project which has previously involved the analysis of a transcript of an interpreted police interview with a suspect in a murder case. I will mention the findings of the analysis briefly and introduce some new findings based on input from practising interpreters who have shared their experience of adversarial interpreting by completing an online questionnaire. I will try to answer the question of how the presence of two interpreters, or an interpreter and a monitoring participant, in the same speech event impacts on the communication process. I will also address the issue of forensic linguistic arbitration in cases where incompetent interpreting has been identified or an expert opinion is sought in relation to an adversarial interpreting event of significance to a legal dispute. References Berk-Seligson (2002), The Bilingual Courtroom: Court Interpreters in the Judicial Process, University of Chicago Press. Hayes, A. and Hale, S. (2010), "Appeals on incompetent interpreting", Journal of Judicial Administration 20.2, 119-130. Phelan, M. (2011), "Legal Interpreters in the news in Ireland", Translation and Interpreting 3.1, 76-105.