TY - JOUR
T1 - Impact of protein domains on PE-PGRS30 polar localization in Mycobacteria
AU - De Maio, Flavio
AU - Maulucci, Giuseppe
AU - Minerva, Mariachiara
AU - Anoosheh, Saber
AU - Palucci, Ivana
AU - Iantomasi, Raffaella
AU - Palmieri, Valentina
AU - Camassa, Serena
AU - Sali, Michela
AU - Sanguinetti, Maurizio
AU - Bitter, Wilbert
AU - Manganelli, Riccardo
AU - De Spirito, Marco
AU - Delogu, Giovanni
PY - 2014/11/12
Y1 - 2014/11/12
N2 - PE-PGRS proteins are unique to the Mycobacterium tuberculosis complex and a number of other pathogenic mycobacteria. PE-PGRS30, which is required for the full virulence of M. tuberculosis (Mtb), has three main domains, i.e. an N-terminal PE domain, repetitive PGRS domain and the unique C-terminal domain. To investigate the role of these domains, we expressed a GFP-tagged PE-PGRS30 protein and a series of its functional deletion mutants in different mycobacterial species ( Mtb, Mycobacterium bovis BCG and Mycobacterium smegmatis ) and analysed protein localization by confocal microscopy. We show that PE-PGRS30 localizes at the mycobacterial cell poles in Mtb and M. bovis BCG but not in M. smegmatis and that the PGRS domain of the protein strongly contributes to protein cellular localization in Mtb. Immunofluorescence studies further showed that the unique C-terminal domain of PE-PGRS30 is not available on the surface, except when the PGRS domain is missing. Immunoblot demonstrated that the PGRS domain is required to maintain the protein strongly associated with the non-soluble cellular fraction. These results suggest that the repetitive GGA-GGN repeats of the PGRS domain contain specific sequences that contribute to protein cellular localization and that polar localization might be a key step in the PE-PGRS30-dependent virulence mechanism.
AB - PE-PGRS proteins are unique to the Mycobacterium tuberculosis complex and a number of other pathogenic mycobacteria. PE-PGRS30, which is required for the full virulence of M. tuberculosis (Mtb), has three main domains, i.e. an N-terminal PE domain, repetitive PGRS domain and the unique C-terminal domain. To investigate the role of these domains, we expressed a GFP-tagged PE-PGRS30 protein and a series of its functional deletion mutants in different mycobacterial species ( Mtb, Mycobacterium bovis BCG and Mycobacterium smegmatis ) and analysed protein localization by confocal microscopy. We show that PE-PGRS30 localizes at the mycobacterial cell poles in Mtb and M. bovis BCG but not in M. smegmatis and that the PGRS domain of the protein strongly contributes to protein cellular localization in Mtb. Immunofluorescence studies further showed that the unique C-terminal domain of PE-PGRS30 is not available on the surface, except when the PGRS domain is missing. Immunoblot demonstrated that the PGRS domain is required to maintain the protein strongly associated with the non-soluble cellular fraction. These results suggest that the repetitive GGA-GGN repeats of the PGRS domain contain specific sequences that contribute to protein cellular localization and that polar localization might be a key step in the PE-PGRS30-dependent virulence mechanism.
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U2 - 10.1371/journal.pone.0112482
DO - 10.1371/journal.pone.0112482
M3 - Article
AN - SCOPUS:84911466492
VL - 9
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 11
M1 - e112482
ER -