Biomaterial Database

Isolation and phenotypic characterization of Myxococcus xanthus mutants which are defective in sensing negative stimuli. 1994

W Shi, and T Köhler, and D R Zusman

Department of Molecular and Cell Biology, University of California, Berkeley 94720.

Myxococcus xanthus is a gram-negative gliding bacterium that exhibits a complex life cycle. Exposure of M. xanthus to chemicals like dimethyl sulfoxide (DMSO) at nondeleterious concentrations or the depletion of nutrients caused several negative responses by the cells. DMSO (> 0.1 M) or nutrient depletion triggered a repellent response: cell swarming was inhibited and FrzCD (a methyl-accepting chemotaxis protein) was demethylated; higher concentrations of DMSO (> 0.3 M) or prolonged starvation induced an additional response which involved cellular morphogenesis: DMSO caused cells to convert from rod-shaped vegetative cells to spherical, environmentally resistant "DMSO spores," and starvation induced myxospore formation in the fruiting bodies. In order to investigate the nature of these responses, we isolated a number of mutants defective in negative chemotaxis and/or sporulation. Characterization of these mutants indicated that negative chemotaxis plays an important role in colony swarming and in developmental aggregation. In addition, the results revealed some of the major interrelationships between the signal transduction pathways which respond to negative stimuli: (i) DMSO exposure and starvation were initially sensed by different systems, the neg system for DMSO and the stv system for starvation; (ii) the repellent response signals triggered by DMSO or starvation were then relayed by the frz signal transduction system; mutants defective in these responses showed altered FrzCD methylation patterns; and (iii) the morphogenesis signals in response to DMSO or starvation utilize a group of genes involved in sporulation (spo).

UI	MeSH Term	Description	Entries
D008565	Membrane Proteins	Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.	Cell Membrane Protein,Cell Membrane Proteins,Cell Surface Protein,Cell Surface Proteins,Integral Membrane Proteins,Membrane-Associated Protein,Surface Protein,Surface Proteins,Integral Membrane Protein,Membrane Protein,Membrane-Associated Proteins,Membrane Associated Protein,Membrane Associated Proteins,Membrane Protein, Cell,Membrane Protein, Integral,Membrane Proteins, Integral,Protein, Cell Membrane,Protein, Cell Surface,Protein, Integral Membrane,Protein, Membrane,Protein, Membrane-Associated,Protein, Surface,Proteins, Cell Membrane,Proteins, Cell Surface,Proteins, Integral Membrane,Proteins, Membrane,Proteins, Membrane-Associated,Proteins, Surface,Surface Protein, Cell
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D002449	Cell Aggregation	The phenomenon by which dissociated cells intermixed in vitro tend to group themselves with cells of their own type.	Aggregation, Cell,Aggregations, Cell,Cell Aggregations
D002633	Chemotaxis	The movement of cells or organisms toward or away from a substance in response to its concentration gradient.	Haptotaxis
D004121	Dimethyl Sulfoxide	A highly polar organic liquid, that is used widely as a chemical solvent. Because of its ability to penetrate biological membranes, it is used as a vehicle for topical application of pharmaceuticals. It is also used to protect tissue during CRYOPRESERVATION. Dimethyl sulfoxide shows a range of pharmacological activity including analgesia and anti-inflammation.	DMSO,Dimethyl Sulphoxide,Dimethylsulfoxide,Dimethylsulphinyl,Dimethylsulphoxide,Dimexide,Rheumabene,Rimso,Rimso 100,Rimso-50,Sclerosol,Sulfinylbis(methane),Rimso 50,Rimso50,Sulfoxide, Dimethyl,Sulphoxide, Dimethyl
D000072236	Methyl-Accepting Chemotaxis Proteins	Transmembrane sensor receptor proteins that are central components of the chemotactic systems of a number of motile bacterial species which include ESCHERICHIA COLI and SALMONELLA TYPHIMURIUM. Methyl-accepting chemotaxis proteins derive their name from a sensory adaptation process which involves methylation at several glutamyl residues in their cytoplasmic domain. Methyl-accepting chemotaxis proteins trigger chemotactic responses across spatial chemical gradients, causing organisms to move either toward favorable stimuli or away from toxic ones.	Methyl-Accepting Chemotaxis Protein,MACP-I,MACP-II,Methyl Accepting Chemotaxis Protein 1,Methyl Accepting Chemotaxis Protein 2,Methyl Accepting Chemotaxis Protein 3,Methyl-Accepting Chemotaxis Protein I,Methyl-Accepting Chemotaxis Protein II,Methyl-Accepting Chemotaxis Protein III,Chemotaxis Protein, Methyl-Accepting,Chemotaxis Proteins, Methyl-Accepting,Methyl Accepting Chemotaxis Protein,Methyl Accepting Chemotaxis Protein I,Methyl Accepting Chemotaxis Protein II,Methyl Accepting Chemotaxis Protein III,Methyl Accepting Chemotaxis Proteins,Protein, Methyl-Accepting Chemotaxis,Proteins, Methyl-Accepting Chemotaxis
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial
D013171	Spores, Bacterial	Heat and stain resistant, metabolically inactive bodies formed within the vegetative cells of bacteria of the genera Bacillus and Clostridium.	Bacterial Spores,Bacterial Spore,Spore, Bacterial
D016941	Myxococcus xanthus	A species of gliding bacteria found on soil as well as in surface fresh water and coastal seawater.