Distinct mitochondrial HSP70 homologues conserved in various Leishmania species suggest novel biological functions.
We report the identification of two distinct homologues of the 70-kDa mitochondrial heat shock protein (mtHSP70) from Leishmania chagasi/Leishmania infantum (Lc2.1 and Lc2.2). In Leishmania species, multiple genes encoding Lc2.2 are present whilst single genes encode Lc2.1. Strikingly, genes encoding Lc2.1-like proteins are absent from Trypanosoma species. Lc2.2 is characterized by a poly-glutamine rich C-terminus, absent from Lc2.1 or mtHSP70 homologues outside the trypanosomatids. Lc2.1 displays unique substitutions within its peptide-binding domain which modify amino acids strictly conserved in cytoplasmic and mitochondrial HSP70 proteins alike. Affinity purified antibodies recognize mainly a single protein in extracts from promastigotes/epimastigotes of various Leishmania/Trypanosoma species. Upon differentiation of Leishmania amazonensis into amastigotes a second protein (presumably Lc2.1) is induced and becomes the predominant mtHSP70 homologue expressed. Subcellular localization of these proteins was investigated and ratified a distribution throughout the mitochondrial matrix. Our results imply novel mtHSP70 functions which evolved within the genus Leishmania.
Campos
Rodrigo M
RM
Centro de Pesquisas Aggeu Magalhães, Fiocruz, Avenida Moraes Rego s/n., Campus UFPE, Recife, PE 50670-420, Brazil.
Nascimento
Mirna
M
Ferraz
J Cândido
JC
Pereira
Mariana M C
MM
Rocha
Pollyanna O
PO
Thompson
Glória M
GM
Cysne-Finkelstein
Léa
L
Figueiredo
Regina C B Q
RC
de Melo Neto
Osvaldo P
OP
D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology; D003429:Cross Reactions; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics* / Q000276:immunology; D018314:Leishmania infantum / Q000235:genetics*; D024101:Mitochondrial Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014345:Trypanosoma / Q000235:genetics
D000913:Antibodies, Protozoan; D016054:DNA, Protozoan; D018840:HSP70 Heat-Shock Proteins; D024101:Mitochondrial Proteins; D015800:Protozoan Proteins