Molecular Biology Commons^™

Mechanism Of N-Methylation By The Trna M1g37 Methyltransferase Trm5., Thomas Christian, Georges Lahoud, Cuiping Liu, Katherine Hoffmann, John J Perona, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

Trm5 is a eukaryal and archaeal tRNA methyltransferase that catalyzes methyl transfer from S-adenosylmethionine (AdoMet) to the N(1) position of G37 directly 3' to the anticodon. While the biological role of m(1)G37 in enhancing translational fidelity is well established, the catalytic mechanism of Trm5 has remained obscure. To address the mechanism of Trm5 and more broadly the mechanism of N-methylation to nucleobases, we examined the pH-activity profile of an archaeal Trm5 enzyme, and performed structure-guided mutational analysis. The data reveal a marked dependence of enzyme-catalyzed methyl transfer on hydrogen ion equilibria: the single-turnover rate constant for methylation increases by one …

The Mir-15/107 Group Of Microrna Genes: Evolutionary Biology, Cellular Functions, And Roles In Human Diseases, John R. Finnerty, Wang-Xia Wang, Sébastien S. Hébert, Bernard R. Wilfred, Guogen Mao, Peter T. Nelson

Pathology and Laboratory Medicine Faculty Publications

The miR-15/107 group of microRNA (miRNA) gene is increasingly appreciated to serve key functions in humans. These miRNAs regulate gene expression involved in cell division, metabolism, stress response, and angiogenesis in vertebrate species. The miR-15/107 group has also been implicated in human cancers, cardiovascular disease and neurodegenerative disease, including Alzheimer's disease. Here we provide an overview of the following: (1) the evolution of miR-15/107 group member genes; (2) the expression levels of miRNAs in mammalian tissues; (3) evidence for overlapping gene-regulatory functions by different miRNAs; (4) the normal biochemical pathways regulated by miR-15/107 group miRNAs; and (5) the roles played …

Notch1 Functions As A Tumor Suppressor In A Model Of K-Ras–Induced Pancreatic Ductal Adenocarcinoma, Linda Hanlon, Jacqueline L Avila, Renée M Demarest, Scott Troutman, Megan Allen, Francesca Ratti, Anil K Rustgi, Ben Z Stanger, Fred Radtke, Volkan Adsay, Fenella Long, Anthony J Capobianco, Joseph L Kissil

Rowan-Virtua School of Osteopathic Medicine Departmental Research

K-ras is the most commonly mutated oncogene in pancreatic cancer and its activation in murine models is sufficient to recapitulate the spectrum of lesions seen in human pancreatic ductal adenocarcinoma (PDAC). Recent studies suggest that Notch receptor signaling becomes reactivated in a subset of PDACs, leading to the hypothesis that Notch1 functions as an oncogene in this setting. To determine whether Notch1 is required for K-ras-induced tumorigenesis, we used a mouse model in which an oncogenic allele of K-ras is activated and Notch1 is deleted simultaneously in the pancreas. Unexpectedly, the loss of Notch1 in this model resulted in increased …

The Globin Gene Family Of The Cephalochordate Amphioxus: Implications For Chordate Globin Evolution, Bettina Ebner, Georgia Panopoulou, Serge N. Vinogradov, Laurent Kiger, Michael C. Marden, Thorsten Burmester, Thomas Hankeln

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

The lancelet amphioxus (Cephalochordata) is a close relative of vertebrates and thus may enhance our understanding of vertebrate gene and genome evolution. In this context, the globins are one of the best studied models for gene family evolution. Previous biochemical studies have demonstrated the presence of an intracellular globin in notochord tissue and myotome of amphioxus, but the corresponding gene has not yet been identified. Genomic resources of Branchiostoma floridae now facilitate the identification, experimental confirmation and molecular evolutionary analysis of its globin gene repertoire.

Results

We show that B. floridae harbors at least fifteen paralogous globin genes, …

Prospects And Pits On The Path Of Biomimetics: The Case Of Tooth Enamel, Vuk Uskoković

Pharmacy Faculty Articles and Research

This review presents a discourse on challenges in understanding and imitating the process of amelogenesis in vitro on the molecular scale. In light of the analysis of imitation of the growth of dental enamel, it also impends on the prospects and potential drawbacks of the biomimetic approach in general. As the formation of enamel proceeds with the protein matrix guiding the crystal growth, while at the same time conducting its own degradation and removal, it is argued that three aspects of amelogenesis need to be induced in parallel: a) crystal growth; b) protein assembly; c) proteolytic degradation. A particular emphasis …