Metabolic regulation underlying stalk synthesis in Caulobacter crescentus

Kevin De Young
Caulobacter crescentus is a gram-negative α-proteobacterium known for its characteristic adhesive stalk and a tolerance to nutrient deprivation. Found mostly in oligotrophic (nutrient-depleted) aquatic environments, Caulobacter responds to changes in resource availability with dynamic metabolic and morphological alterations. We isolated a mutant strain with reduced stalk length; the mutation mapped to gene CC3617, a mannose 6-phosphate isomerase. During phosphate starvation, wild-type cells
more » ... wild-type cells maintain a 1:1 ratio of mannose 6-phosphate (M6P) and fructose 6-phosphate (F6P). Our CC3617 mutant strain, by contrast, has a relative increase in F6P. The decrease in M6P correlates with low levels of exopolysaccharide and O-antigen synthesis. Interestingly, we find that the CC3617 mutant strain does not readily enter stationary phase; rather it continuously increases cell number and represses stationary-phase gene expression. Forced induction of stationary phase promotes stalk length recovery in the CC3617 mutant strain. Furthermore, deletion of stationary phase genes in wild-type cells produce a reduction in stalk length.
doi:10.7282/t3-ngdz-nx12 fatcat:7sycb23vwndxplbljpudmwi2sm