TY - JOUR
T1 - Molecular characterization and ultrastructural localization of Plasmodium falciparum Hsp 60
AU - Das, Ashis
AU - Syin, Chiang
AU - Fujioka, Hisashi
AU - Zheng, Hong
AU - Goldman, Neil
AU - Aikawa, Masamichi
AU - Kumar, Nirbhay
N1 - Funding Information:
We thank Dr J. Sacci for providing us with the P. yoelii exo-erythrocytic schizont slides. This work was supported by NIH grant AI 31589 (NK) and in part by grants to MA from the US Agency for International Development (DPE-936-6001-29), the NIH (AI-35827) and a grant-in-aid for scientific research on priority areas from the Ministry of Education, Science, Sports and Culture of Japan.
PY - 1997/9
Y1 - 1997/9
N2 - Heat shock proteins (Hsp) are a group of highly conserved proteins which are widely represented phylogenetically. Genes for members of the Hsp 70, 90 and 60 families have been cloned from the human malaria parasite plasmodium falciparum. In this study, we have cloned and expressed the P. falciparum Hsp 60 (PfHsp60) in E. coli. The sequence analysis identified a previously unknown intron of 257 bp beginning after the nucleotide 142 in the coding sequence. Antisera raised against the recombinant PfHsp60 was employed in immunoprecipitation studies with biosynthetically labeled parasite extracts to investigate regulation of expression of PfHsp60 at various temperatures. In contrast to the three to four fold accumulation of PfHsp60 transcripts in heat shocked parasites (37-40°C), the expression of PfHsp60 was not induced in the blood stages of P. falciparum. On the other hand, the effect of heat induction on PfHsp70 was seen both at the level of specific mRNA and protein. In these studies we also observed co-immunoprecipitation of a number of other cellular proteins suggesting possible interaction with PfHsp60. Immunofluorescence analysis indicated the presence of PfHsp60 in the cytoplasm of all the various stages of the parasite. In addition, immunoelectron microscopic analysis distinctly localized PfHsp60 in the mitochondrion of P. falciparum. This study suggests that different mechanisms are involved in the regulation of expression of various members of the heat shock proteins in the parasite.
AB - Heat shock proteins (Hsp) are a group of highly conserved proteins which are widely represented phylogenetically. Genes for members of the Hsp 70, 90 and 60 families have been cloned from the human malaria parasite plasmodium falciparum. In this study, we have cloned and expressed the P. falciparum Hsp 60 (PfHsp60) in E. coli. The sequence analysis identified a previously unknown intron of 257 bp beginning after the nucleotide 142 in the coding sequence. Antisera raised against the recombinant PfHsp60 was employed in immunoprecipitation studies with biosynthetically labeled parasite extracts to investigate regulation of expression of PfHsp60 at various temperatures. In contrast to the three to four fold accumulation of PfHsp60 transcripts in heat shocked parasites (37-40°C), the expression of PfHsp60 was not induced in the blood stages of P. falciparum. On the other hand, the effect of heat induction on PfHsp70 was seen both at the level of specific mRNA and protein. In these studies we also observed co-immunoprecipitation of a number of other cellular proteins suggesting possible interaction with PfHsp60. Immunofluorescence analysis indicated the presence of PfHsp60 in the cytoplasm of all the various stages of the parasite. In addition, immunoelectron microscopic analysis distinctly localized PfHsp60 in the mitochondrion of P. falciparum. This study suggests that different mechanisms are involved in the regulation of expression of various members of the heat shock proteins in the parasite.
KW - Chaperonin
KW - Heat shock protein 60
KW - Malaria
KW - Mitochondrion
KW - Plastnodium falciparum
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U2 - 10.1016/S0166-6851(97)00081-9
DO - 10.1016/S0166-6851(97)00081-9
M3 - Article
C2 - 9274871
AN - SCOPUS:0030835367
VL - 88
SP - 95
EP - 104
JO - Molecular and Biochemical Parasitology
JF - Molecular and Biochemical Parasitology
SN - 0166-6851
IS - 1-2
ER -