The sequence spectrum of frameshift reversions obtained with a novel adaptive mutation assay in .

Research on the mechanisms of adaptive mutagenesis in resting, non-replicating cells relies on appropriate mutation assays. Here we provide a novel procedure for the detection of frameshift-reverting mutations in yeast. Proliferation of non-reverted cells in this assay is suppressed by the lack of a fermentable carbon source.

Glucose starvation as a selective tool for the study of adaptive mutations in Saccharomyces cerevisiae.

Mutations not only arise in proliferating cells but also in resting - thus non-replicating - cells. Such stationary-phase mutations may occasionally enable an escape from growth repression and e.g.

Novel double and single ryanodine receptor 1 variants in two Austrian malignant hyperthermia families.

Background: Malignant hyperthermia (MH) is a potentially lethal genetic disorder in response to volatile anesthetics and depolarizing muscle relaxants. To support the claim that a novel genetic variant causes MH, it is necessary to demonstrate that it has significant effects on the sensitivity of the ryanodine receptor (RYR1) calcium channel. In this study we focused on 2 Austrian families with strong MH disposition and new RYR1 variants.

The relevance of oxidative stress and cytotoxic DNA lesions for spontaneous mutagenesis in non-replicating yeast cells.

Mutations arising during times of cell cycle-arrest may considerably contribute to aging and cancerogenesis. Endogenous oxidative stress could be one of the major triggers for these mutations. We used Saccharomyces cerevisiae cells, arrested by starvation for the essential amino acid lysine, to study the occurrence of reactive oxygen species (ROS), abasic (AP) sites and double strand breaks (DSBs).

A mutation-promotive role of nucleotide excision repair in cell cycle-arrested cell populations following UV irradiation.

Growing attention is paid to the concept that mutations arising in stationary, non-proliferating cell populations considerably contribute to evolution, aging, and pathogenesis. If such mutations are beneficial to the affected cell, in the sense of allowing a restart of proliferation, they are called adaptive mutations. In order to identify cellular processes responsible for adaptive mutagenesis in eukaryotes, we study frameshift mutations occurring during auxotrophy-caused cell cycle arrest in the model organism Saccharomyces cerevisiae.

The nuclear actin-related protein of Saccharomyces cerevisiae, Arp4, directly interacts with the histone acetyltransferase Esa1p.

Ten actin-related proteins are known in Saccharomyces cerevisiae, classified into Arps1-10 according to their relatedness to actin. Arp4, a nuclear protein, essential for viability of S. cerevisiae, is a component of at least three chromatin-modifying complexes, one of which is the histone acetyltransferase (HAT) complex NuA4.

Novel regulatory properties of Saccharomyces cerevisiae Arp4.

ARP4, an essential gene of Saccharomyces cerevisiae, codes for a nuclear actin-related protein. Arp4 is a subunit of several chromatin-modifying complexes and is known to be involved in the transcriptional regulation in yeast. We used a mutant strain with a single amino acid substitution (G161D) in the conserved actin fold domain to investigate the influence of Arp4 on stress and nitrogen catabolite repression genes.

Identification of the cytolinker protein plectin in neuronal cells - expression of a rodless isoform in neurons of the rat superior cervical ganglion.

Plectin, a large (> 500 kDa) dumbbell-shaped cytolinker protein plays an important role in the organization of the cytoskeletal network and the maintenance of cell integrity in a wide variety of tissues and cell types. Earlier experiments revealed the presence of plectin in the central nervous system, whereas the expression in the peripheral nervous system remained unclear. Our results obtained with reverse transcriptase-PCR (RT-PCR) provide evidence that plectin is expressed in structures of the rat peripheral nervous system.

Epistatic participation of REV1 and REV3 in the formation of UV-induced frameshift mutations in cell cycle-arrested yeast cells.

Mutations arising in times of cell cycle arrest may provide a selective advantage for unicellular organisms adapting to environmental changes. For multicellular organisms, however, they may pose a serious threat, in that such mutations in somatic cells contribute to carcinogenesis and ageing. The budding yeast Saccharomyces cerevisiae presents a convenient model system for studying the incidence and the mechanisms of stationary-phase mutation in a eukaryotic organism.