title: Babesia divergens: identification and characterization of BdHSP-20, a small heat shock protein.
abstract: This study describes the identification and characterization of the Babesia divergens alpha-crystallin/small heat shock protein 20 (BdHSP-20). BdHSP-20 was recognized by the DG7 monoclonal antibody (DG7 mAb) originally produced by Precigout et al. [Precigout, E., Valentin, A., Carcy, B., Gorenflot, A., Nakamura, K., Aikawa, M., Schrevel, J. 1993. Babesia divergens: characterization of a 17-kDa merozoite membrane protein. Experimental Parasitology 77, 425-434] against B. divergens merozoites. We used DG7 mAb to immunoscreen a B. divergens cDNA library to clone the gene encoding the small heat shock protein. Bdhsp-20 is a single copy gene interrupted by one intron. The deduced gene product (BdHSP-20) clearly belongs to the alpha-crystallin family and shows significant homology to Babesia bovis, Plasmodium falciparum and Toxoplasma gondii sHSPs, with the highest degree of sequence identity around the catalytic domain. Nutritient stress (serum depletion) treatment of the parasites induced the upregulation of BdHSP-20 gene expression observed by semi-quantitative PCR and immunoprecipitation. This regulation pattern suggests that BdHSP-20 could probably be of importance for parasite survival in the case of environmental stress. BdHSP-20 has previously been shown to be highly conserved among different strains and antibodies against the protein drastically reduce parasitemia in vitro.
authors.affiliation: Department of Blood-Borne Parasites, Lindsley Kimball Research Institute, The New York Blood Center, 310 E. 67th Street, New York, NY 10021, USA.
authors.forename: Estrella
authors.initials: E
authors.lastname: Montero
authors.forename: Marilis
authors.initials: M
authors.lastname: Rodriguez
authors.forename: Luis-Miguel
authors.initials: LM
authors.lastname: Gonzalez
authors.forename: Cheryl A
authors.initials: CA
authors.lastname: Lobo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001403:Babesia / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D015139:Blotting, Southern; D015153:Blotting, Western; D003001:Cloning, Molecular; D003429:Cross Reactions; D016054:DNA, Protozoan / Q000737:chemistry / Q000302:isolation & purification; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D015723:Gene Library; D050886:HSP20 Heat-Shock Proteins / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D047468:Immunoprecipitation; D007438:Introns; D008969:Molecular Sequence Data; D016053:RNA, Protozoan / Q000737:chemistry / Q000302:isolation & purification; D015183:Restriction Mapping; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015854:Up-Regulation
chemical_list: D000911:Antibodies, Monoclonal; D016054:DNA, Protozoan; D050886:HSP20 Heat-Shock Proteins; D016053:RNA, Protozoan