Beta-D-Allose inhibits fruiting body formation and sporulation in Myxococcus xanthus.
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.
Chavira
Marielena
M
Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA 90095-1668, USA.
Cao
Nga
N
Le
Karen
K
Riar
Tanveer
T
Moradshahi
Navid
N
McBride
Melinda
M
Lux
Renate
R
Shi
Wenyuan
W
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
D003470:Culture Media; C002055:allose; D005941:Glucokinase; D005947:Glucose