Internal Seminar: Yamamoto Unit and Miller Unit

Join us for February's first Internal Seminar Series on Feb. 6, from 17:00 to 18:00 in B503. This month's seminars feature the Cell Signal Unit (Tadashi Yamamoto) and the Physics and Biology Unit (Jonathan Miller).

Cell Signal Unit (Tadashi Yamamoto)

Speaker : Prof. Tadashi Yamamoto

Title : Biology of the mRNA decay machinery-Gene expression is circular

Abstract : We living organisms cope with environmental changes by responding appropriately to various stimuli. The mechanisms behind these responses are becoming clearer through the progress of recent molecular biological studies. One very important mechanism is the control of gene expression, which can be mediated both transcriptionally and post-transcriptionally. Another equally important mechanism lies in signal transduction pathways. In the Cell Signal Unit, we are studying these two biological processes by utilizing mice in which cell surface receptor-mediated signaling or gene expression machinery is abrogated. Here, I will talk about the mRNA decay machinery, CCR4-NOT. CCR4-NOT is a large (2 MDa) protein complex consisting of at least 10 subunits, four of which carry deadenylase activity with the others likely serving as either a scaffold of the complex or as regulators of deadenylation. I show here that targeted disruption of the genes encoding CCR4-NOT complex components in mice allow us to analyze regulatory mechanisms involved in controlling gene expression in response to environmental cues. It also provides excellent animal models for human disease. From these studies it is becoming clear that not only transcriptional but also post-transcriptional mechanisms are important for the regulation of high-order functions in mammals.

Physics and Biology Unit (Jonathan Miller)

Speaker : Kun Gao (Postdoctor)

Title : Finding orthologs genomewide with NO alignment and NO repeatmasking.

Abstract : We introduce a new method to identify positional orthologs: sequence orthologs whose relative locations or genomic contexts are preserved between two genomes. Our method focuses on the local structure of maximal matches within the genomes; based on a novel concept of “nesting," we extract maximal matches that are not nested into other maximal matches as candidates for positional orthologs. Reciprocal best hits of genes containing non-nested matches predict orthologous genes with both high selectivity and high sensitivity. Overall, non-nested matches extracted from genomic intersection are consistent with the exact matches identified by a LastZ alignment.