The funders' perspective: Lessons learned from the National Institutes of Health Diversity Program Consortium evaluation.

Advancing diversity in the biomedical research workforce is critical to the ability of the National Institutes of Health (NIH) to achieve its mission. The NIH Diversity Program Consortium is a unique, 10-year program that builds upon longstanding training and research capacity-building activities to promote workforce diversity. It was designed to rigorously evaluate approaches to enhancing diversity in the biomedical research workforce at the student, faculty, and institutional level.

Increasing Clinician-Scientist Workforce Diversity through the National Institute of General Medical Sciences' Medical Scientist Training Program.

The National Institute of General Medical Sciences Medical Scientist Training Program (MSTP) has been successful in producing clinician-scientists, with a majority of graduates pursuing research-related careers. However, there are a number of areas of continuing concern for the program. In particular, women and individuals from certain racial and ethnic backgrounds remain persistently underrepresented in MSTPs relative to the average college-aged U.

MutSα mismatch repair protein stability is governed by subunit interaction, acetylation, and ubiquitination.

In eukaryotes, DNA mismatch recognition is accomplished by the highly conserved MutSα (Msh2/Msh6) and MutSβ (Msh2/Msh3) complexes. Previously, in the yeast Saccharomyces cerevisiae, we determined that deleting MSH6 caused wild-type Msh2 levels to drop by ∼50%. In this work, we determined that Msh6 steady-state levels are coupled to increasing or decreasing levels of Msh2.

Developing a culture of safety in biomedical research training.

The National Institute of General Medical Sciences (NIGMS) at the U.S. National Institutes of Health (NIH) is committed to supporting the safety of the nation's biomedical research and training environments.

Whole-Genome Sequence and Variant Analysis of W303, a Widely-Used Strain of .

The yeast has emerged as a superior model organism. Selection of distinct laboratory strains of with unique phenotypic properties, such as superior mating or sporulation efficiencies, has facilitated advancements in research. W303 is one such laboratory strain that is closely related to the first completely sequenced yeast strain, S288C.

From the NIH: A Systems Approach to Increasing the Diversity of the Biomedical Research Workforce.

The National Institutes of Health (NIH) is committed to attracting, developing, and supporting the best scientists from all groups as an integral part of excellence in training. Biomedical research workforce diversity, capitalizing on the full spectrum of skills, talents, and viewpoints, is essential for solving complex human health challenges. Over the past few decades, the biomedical research workforce has benefited from NIH programs aimed at enhancing diversity.

The Eukaryotic Mismatch Recognition Complexes Track with the Replisome during DNA Synthesis.

During replication, mismatch repair proteins recognize and repair mispaired bases that escape the proofreading activity of DNA polymerase. In this work, we tested the model that the eukaryotic mismatch recognition complex tracks with the advancing replisome. Using yeast, we examined the dynamics during replication of the leading strand polymerase Polε using Pol2 and the eukaryotic mismatch recognition complex using Msh2, the invariant protein involved in mismatch recognition.

Rapid Identification of Chemoresistance Mechanisms Using Yeast DNA Mismatch Repair Mutants.

Resistance to cancer therapy is a major obstacle in the long-term treatment of cancer. A greater understanding of drug resistance mechanisms will ultimately lead to the development of effective therapeutic strategies to prevent resistance from occurring. Here, we exploit the mutator phenotype of mismatch repair defective yeast cells combined with whole genome sequencing to identify drug resistance mutations in key pathways involved in the development of chemoresistance.

Mutation rates, spectra, and genome-wide distribution of spontaneous mutations in mismatch repair deficient yeast.

DNA mismatch repair is a highly conserved DNA repair pathway. In humans, germline mutations in hMSH2 or hMLH1, key components of mismatch repair, have been associated with Lynch syndrome, a leading cause of inherited cancer mortality. Current estimates of the mutation rate and the mutational spectra in mismatch repair defective cells are primarily limited to a small number of individual reporter loci.

Cell-cycle and DNA damage regulation of the DNA mismatch repair protein Msh2 occurs at the transcriptional and post-transcriptional level.

DNA mismatch repair during replication is a conserved process essential for maintaining genomic stability. Mismatch repair is also implicated in cell-cycle arrest and apoptosis after DNA damage. Because yeast and human mismatch repair systems are well conserved, we have employed the budding yeast Saccharomyces cerevisiae to understand the regulation and function of the mismatch repair gene MSH2.

Proteasome inhibition rescues clinically significant unstable variants of the mismatch repair protein Msh2.

MSH2 is required for DNA mismatch repair recognition in eukaryotes. Deleterious mutations in human MSH2 account for approximately half of the alleles associated with a common hereditary cancer syndrome. Previously, we characterized clinically identified MSH2 missense mutations, using yeast as a model system, and found that the most common cause of defective DNA mismatch repair was low levels of the variant Msh2 proteins.

Two replication regions in the pJM1 virulence plasmid of the marine pathogen Vibrio anguillarum.

Vibrio anguillarum is a fish pathogen that causes vibriosis, a serious hemorrhagic septicemia, in wild and cultured fish. Many serotype O1 strains of this bacterium harbor the 65kb plasmid pJM1 carrying the majority of genes encoding the siderophore anguibactin iron transport system that is one of the most important virulence factors of this bacterium. We previously identified a replication region of the pJM1 plasmid named ori1.

Reciprocal regulation of nuclear import of the yeast MutSalpha DNA mismatch repair proteins Msh2 and Msh6.

DNA mismatch recognition is performed in eukaryotes by two heterodimers known as MutSalpha (Msh2/Msh6) and MutSbeta (Msh2/Msh3) that must reside in the nucleus to function. Two putative Msh2 nuclear localization sequences (NLS) were characterized by fusion to green fluorescent protein (GFP) and site-directed mutagenesis in the context of Msh2. One NLS functioned in GFP targeting assays and both acted redundantly within Msh2.

Ultrastructural analysis of cell fusion in yeast.

The process of creating a single cell from two progenitor cells requires molecular precision to coordinate the events leading to cytoplasmic continuity while preventing lethal cell lysis. Cell fusion characteristically involves the mobilization of fundamental processes, including signaling, polarization, adhesion, and membrane fusion. The yeast Saccharomyces cerevisiae is an ideal model system for examining the events of this critical and well-conserved process.

Functional characterization of pathogenic human MSH2 missense mutations in Saccharomyces cerevisiae.

Hereditary nonpolyposis colorectal cancer (HNPCC) is associated with defects in DNA mismatch repair. Mutations in either hMSH2 or hMLH1 underlie the majority of HNPCC cases. Approximately 25% of annotated hMSH2 disease alleles are missense mutations, resulting in a single change out of 934 amino acids.

Role of transcription factor Kar4 in regulating downstream events in the Saccharomyces cerevisiae pheromone response pathway.

Yeast Kar4 is a putative transcription factor required for karyogamy (the fusion of haploid nuclei during mating) and possibly other functions. Previously known to be required only for the transcriptional induction of KAR3 and CIK1, microarray experiments identified many genes regulated by Kar4 in both mating and mitosis. Several gene clusters are positively or negatively regulated by mating pheromone in a Kar4-dependent manner.

Lrg1p Is a Rho1 GTPase-activating protein required for efficient cell fusion in yeast.

To identify additional cell fusion genes in Saccharomyces cerevisiae, we performed a high-copy suppressor screen of fus2Delta. Higher dosage of three genes, BEM1, LRG1, and FUS1, partially suppressed the fus2Delta cell fusion defect. BEM1 and FUS1 were high-copy suppressors of many cell-fusion-defective mutations, whereas LRG1 suppressed only fus2Delta and rvs161Delta.

Characterization of pathogenic human MSH2 missense mutations using yeast as a model system: a laboratory course in molecular biology.

This work describes the project for an advanced undergraduate laboratory course in cell and molecular biology. One objective of the course is to teach students a variety of cellular and molecular techniques while conducting original research. A second objective is to provide instruction in science writing and data presentation by requiring comprehensive laboratory reports modeled on the primary literature.