Cyclic nucleotides in procaryotes.

Catabolite repression in yeasts is not associated with low levels of cAMP

“…The results presented show that although catabolite repression is widely extended among microorganisms the underlying mechanisms are not uniform. In fact, it has been shown that while in Escherichia coli cAMP is necessary for relieving catabolite repression [2] this is not the case for Pseudomonas [36], Bacillus [37] or Tetrahymena [38,39].…”

“…It is therefore concluded that in yeasts catabolite repression is not mediated by a lowering of the intracellular concentration of CAMP.Catabolite repression in yeasts is a well known phenomenon [I] but its underlying mechanism has not been yet established. Since in bacteria catabolite repression is correlated with lowered levels of CAMP (for a review see [2]), it has been tempting to assume that the same situation ocurred in yeast. Indeed some early data on CAMP levels appeared to confirm this idea [3,4] and a more recent review on the subject agreed also with this view [5].…”

cAMP levels withinMycobacterium tuberculosisandMycobacterium bovisBCG increase upon infection of macrophages

“…The M. tuberculosis genome encodes 15 adenylyl cyclases (McCue et al, 2000), most of which have been shown to be functional using in vitro biochemical approaches (Shenoy & Visweswariah, 2006). Mycobacteria produce high levels of endogenous cAMP, compared with other bacteria (Padh & Venkitasubramanian, 1976a, b;Lee, 1979;Botsford, 1981), consistent with this abundance of adenylyl cyclases. Exogenously added cAMP affects gene expression in tuberculosis-complex mycobacteria in response to environmental conditions such as hypoxia (Gazdik & McDonough, 2005).…”

“…Adenosine 3 0 ,5 0 -cyclic monophosphate(cAMP) is an important signaling molecule in many bacterial and eukaryotic cells (Botsford, 1981;Botsford & Harman, 1992;Daniel et al, 1998). However, little is known about the role of cAMP in mycobacteria, despite its potential importance to M. tuberculosis metabolism and pathogenesis (Lowrie et al, 1975;Bai et al, 2005Bai et al, , 2007Gazdik & McDonough, 2005;Rickman et al, 2005;Spreadbury et al, 2005).…”

Cyclic adenosine 3′,5′-monophosphate in Rhodopseudomonas capsulata

“…Cyclic adenosine 3',5'-monophosphate (cAMP) has been shown to be present in a high number of bacterial species and other microorganisms. In addition to the well-known role of cAMP in the control of initiation of transcription of inducible catabolic operons [1,2], this molecule appears to affect many other functions [3], among them, lysogeny by bacteriophage, replication of plasmids, a variety of envelope properties including regulation of synthesis of flagella and pili, antibiotic susceptibility and regulation of different membrane-associated enzymes. However, the presence and/or effect of this nucleotide in photosynthetic bacteria has never been reported.…”