title: Beta-D-Allose inhibits fruiting body formation and sporulation in Myxococcus xanthus.
abstract: Myxococcus xanthus, a gram-negative soil bacterium, responds to amino acid starvation by entering a process of multicellular development which culminates in the assembly of spore-filled fruiting bodies. Previous studies utilizing developmental inhibitors (such as methionine, lysine, or threonine) have revealed important clues about the mechanisms involved in fruiting body formation. We used Biolog phenotype microarrays to screen 384 chemicals for complete inhibition of fruiting body development in M. xanthus. Here, we report the identification of a novel inhibitor of fruiting body formation and sporulation, beta-d-allose. beta-d-Allose, a rare sugar, is a member of the aldohexose family and a C3 epimer of glucose. Our studies show that beta-d-allose does not affect cell growth, viability, agglutination, or motility. However, beta-galactosidase reporters demonstrate that genes activated between 4 and 14 h of development show significantly lower expression levels in the presence of beta-d-allose. Furthermore, inhibition of fruiting body formation occurs only when beta-d-allose is added to submerged cultures before 12 h of development. In competition studies, high concentrations of galactose and xylose antagonize the nonfruiting response to beta-d-allose, while glucose is capable of partial antagonism. Finally, a magellan-4 transposon mutagenesis screen identified glcK, a putative glucokinase gene, required for beta-d-allose-mediated inhibition of fruiting body formation. Subsequent glucokinase activity assays of the glcK mutant further supported the role of this protein in glucose phosphorylation.
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA 90095-1668, USA.
authors.forename: Marielena
authors.initials: M
authors.lastname: Chavira
authors.forename: Nga
authors.initials: N
authors.lastname: Cao
authors.forename: Karen
authors.initials: K
authors.lastname: Le
authors.forename: Tanveer
authors.initials: T
authors.lastname: Riar
authors.forename: Navid
authors.initials: N
authors.lastname: Moradshahi
authors.forename: Melinda
authors.initials: M
authors.lastname: McBride
authors.forename: Renate
authors.initials: R
authors.lastname: Lux
authors.forename: Wenyuan
authors.initials: W
authors.lastname: Shi
mesh_terms: D003470:Culture Media; D005798:Genes, Bacterial; D005941:Glucokinase / Q000235:genetics / Q000502:physiology; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology*; D016941:Myxococcus xanthus / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D010766:Phosphorylation; D013171:Spores, Bacterial / Q000187:drug effects; D013997:Time Factors
chemical_list: D003470:Culture Media; C002055:allose; D005941:Glucokinase; D005947:Glucose