INVESTIGADORES
FARBER Marisa Diana
congresos y reuniones científicas
Título:
From Perforin like Protein (PLP) annotation in Babesia bigemina to evolutionary history of MACPF-DOMAIN in Piroplasmida (Apicomplexa)
Autor/es:
REGO N; PETRIGH R; NAYA H; FARBER M
Lugar:
New Orleans
Reunión:
Conferencia; 11th International Conference on Molecular Epidemiology and Evolutionary Genetics of Infectious Diseases,; 2012
Institución organizadora:
Elsevier
Resumen:
Babesia bigemina and B. bovis are intraerythrocytic
apicomplexans that causes babesiosis in cattle, a tick-transmitted disease
worldwide distributed. Some of the steps involved in host cell-infection depend
on secreted proteins. Studies in Plasmodium yoelii reported a secreted
protein family containing membrane-attack complex/perforin (MACPF)-like domains
known as Perforin Like Proteins (PLP). Aiming to understand PLPs importance for
babesia transmission, we searched for plp
gene repertoire in B. bigemina and studied the phylogenetic
relationships with previously known apicomplexa PLPs.
MACPF domains from annotated B. bovis PLPs were used to perform
TBLASTN searches on B. bigemina contigs. FGENESH and Glimmer HMM trained
with P. falciparum and B. bovis respectively, were used for annotation.
Manual refinement of predictions was performed with Artemis. Due to the high
divergence of apicomplexan PLPs, phylogenetic analysis was focused on the MACPF
domains. The alignment was
assisted by a structural profile derived from the superimposition of known
structures and phylogeny inferred trough Maximum Likelihood
ptimization. Alternatively, a simultaneous Bayesian estimation of
alignment and phylogeny was conducted (Bali-Phy).
Eight coding sequences with MACPF domain were determined in B.
bigemina partial assembly. In a novel arrangement, B. bovis is
predicted to encode multiple MACPF domains (3) within a single protein.
However, B. bigemina does not show this peculiar PLP structure. RT-PCR
experiments revealed the expression of all plp
genes in the B. bigemina vertebrate stage.
Evolutionary history is complex in PLP family, as can be deduced from
the inferred tree. Some duplication events preceded piroplasmids and
haemosporidians divergence, while others are exclusive of each lineage. In a
parsimony framework, we infer at least 4 PLPs present in the common ancestor of
Piroplasmida and Haemosporida. The MACPF domain not only expand but also appear
to have gathered at least twice independently in piroplasmids, leading to a
gene structure with 3 domains in B. bovis and T. annulata.