The mce1 proteins of Mycobacterium tuberculosis are involved in the uptake and metabolism of lipids.

FORRELLAD M.A.; KLEPP L.I.; BLANCO F.C.; SANTANGELO M.P.; BIANCO M.V.; GUTIERREZ M.; JACKSON M.; BIGI F.

Potrero de los Funes, San Luis

Congreso; SAIB- 47th Annual Meeting- Argentine Society for Biochemistry and Molecular Biology Research.; 2011

Sociedad Argentina de Investigaciones Bioquímicas y Biología Molecular.

The Mce proteins of M. tuberculosis have been implicated in the entry of the bacterium into the host cells. These proteins are codified in four locus in the M. tuberculosis genome: mce1, -2, -3 and -4, each one includes two yrbE and six mce genes. An in silico analysis have revealed them as transporter systems. Recently, it was demonstrated that Mce4 are involved in cholesterol uptake. Due to, one adaptation of M. tuberculosis to persist into the host cells is its changes to utilizes lipids as carbon source, we analyzed the role of Mce1 proteins into the uptake and metabolism of palmitic acid (pal). We have observed that M. tuberculosis Dmce1 mutant incorpotes less [14C]-pal compared to the wild type (WT) in the first 30min of an uptake experiment. However, after 30min [14C]-pal accumulates in the mutant while the WT remains constant. In addition, by qRT-PCR experiment we observed a correlation between the uptake of pal and the mce1 genes expression. Also, we identified two lipids accumulated in the mutant compared to the WT, when the bacteria were grown with pal as unique carbon source. In this study we also analysed the Mce1 proteins localization and the intracellular traffic of the Dmce1 mutant. Taken together, the results presented here suggest that the Mce1 proteins are a palmitic acid transporter system and perhaps it would be related to the membrane lipids recycling.