Phosphorylation is the major mechanism regulating isocitrate lyase activity in Paracoccidioides brasiliensis yeast cells.

摘要: The glyoxylate cycle plays an essential role for anaplerosis of oxaloacetate during growth microorganisms on carbon sources such as acetate or fatty acids and has been shown to contribute virulence several pathogens. Here, we investigated the transcriptional post-translational regulation key enzyme isocitrate lyase (PbICL) in human pathogenic fungus Paracoccidioides brasiliensis. Although sequence analyses fungal lyases revealed a high phylogenetic conservation, their seems differ significantly. Closely related Aspergillus species regulate at level, whereas Pbicl was constitutively expressed yeast cells. However, only low PbICL activity detected when cells were grown presence glucose. Two-dimensional gel with subsequent antibody hybridization constitutive production PbICL, but glucose coincided extensive protein phosphorylation. Since in vitro dephosphorylation from strongly increased ICL resembled phosphorylation pattern highly active cells, modification main mechanism regulating In agreement, transfer medium without requirement de novo synthesis. Thus, inactivation by is reversible, denoting new strategy rapid adaptation changing environmental conditions.