Role of Exogenous Adenosine Triphosphate in Catabolic and Synthetic Activities of Chlamydia psittaci

Abstract

The synthetic activities of isolated cells of the meningopneumonitis strain (MN) of Chlamydia psittaci were investigated and further observations were made on their catabolic reactions. These observations included the demonstration of CO2 production from aspartate in the presence of pyruvate and the formation of pyruvate from glucose-6-phosphate. Both reactions were enhanced by added adenosine triphosphate (ATP). Of a large number of compounds tested, only glucose-6phosphate, pyruvate, aspartate, and isoleucine were shown to furnish carbons that were incorporated into molecules precipitated by trichloroacetic acid. The reactions with pyruvate, aspartate, and isoleucine were dependent entirely, or almost entirely, on added ATP, and the reaction with glucose-6-phosphate was enhanced by ATP. Except for C02, which greatly stimulated the reactions, the addition of a number of other compounds or a combination of compounds, such as cofactors, amino acids, and purine and pyrimidine bases, did not greatly affect incorporation. About 95% of the activity of the trichloroacetic acid precipitates was recovered in the chloroform-methanol soluble fraction.

Chlamydial metabolism revisited: interspecies metabolic variability and developmental stage-specific physiologic activities

“…Moreover, heterologous expression and characterization of respective C. trachomatis enzymes in E. coli confirmed that they are functional (Iliffe-Lee & McClarty, 1999). Consistent with the earlier experimental observations (Weiss, 1965;Vender & Moulder, 1967;Weiss & Wilson, 1969), genomic data confirmed that Chlamydiaceae lack a hexokinase gene, as well as substrate-specific components of the phosphotransferase system (PTS; Stephens et al, 1998;Kalman et al, 1999;McClarty, 1999;Read et al, 2000Read et al, , 2003Carlson et al, 2005;Thomson et al, 2005;Azuma et al, 2006;Thomson et al, 2008;Mojica et al, 2011;Voigt et al, 2012). The bacteria thus depend on the import of phosphorylated sugar (D-glucose-6-phosphate) from the host cell cytosol, which is likely accomplished by a sugar-phosphate/inorganic-phosphate antiporter (UhpC; McClarty, 1999), the C. pneumoniae homolog of which has been functionally characterized in E. coli (Schw€ oppe et al, 2002).…”

“…starts with the phosphorylated compound and that Chlamydia spp. lack hexokinase (Weiss, 1965;Weiss & Wilson, 1969).…”

Simple Nutrition of Crithidia deanei, a Reduviid Trypanosomatid with an Endosymbiont*

“…growth factors, suitable physical conditions, and even energy, as observed with Chlamydia psittaci which derives energy from the host cell (20). With the exception of Rickettsia quintana, which requires hemin (13), no other rickettsia or similar organism could be grown in cell-free media (19). Examining the differences between essentials required by C. deanei and other lower trypanosomatids might aid in developing media for rickettsiae and similar organisms.…”

Isolation and characterization of macrophage phagosomes containing infectious and heat-inactivated Chlamydia psittaci: two phagosomes with different intracellular behaviors

“…Because the inhibition of phagosome-lysosome fusion is localized to phagosomes containing infectious chlamydiae (the other phagosomes of chlamydia-infected cells continue to fuse with lysosomes) (10), the elements that prevent chlamydial phagosomes from fusing with lysosomes must be present only in the special, parasite-specified, chlamydial phagosomes. Kinetic considerations, the limited metabolic capabilities of chlamydial elementary bodies (26,40,41), and the failure of inhibitors of chlamydial macromolecular synthesis to block the inhibition of phagosome-lysosome fusion all suggest that the factors responsible for this inhibition have their source in the host cell itself. Finally, from analogy with well-characterized systems in which viral proteins promote and inhibit membrane fusion (16,17,25,29,31), the modulators of phagosome-lysosome fusion are most likely to be proteins.…”