STAGE-SPECIFIC EXPRESSION OF THE CALMODULIN GENE IN PLASMODIUM-FALCIPARUM

Citation
Mo. Rojas et M. Wasserman, STAGE-SPECIFIC EXPRESSION OF THE CALMODULIN GENE IN PLASMODIUM-FALCIPARUM, Journal of Biochemistry, 118(6), 1995, pp. 1118-1123
Citations number
52
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biology
Journal title
ISSN journal
0021-924X
Volume
118
Issue
6
Year of publication
1995
Pages
1118 - 1123
Database
ISI
SICI code
0021-924X(1995)118:6<1118:SEOTCG>2.0.ZU;2-Z
Abstract
We studied the synthesis of calmodulin mRNA and of calmodulin during t he asexual cell cycle of Plasmodium falciparum. The expression of the gene was low during the early stages of the erythrocytic asexual cycle . When the parasites were 28 h old the level of mRNA increased steadil y to reach a peak at the age of 40 h. During the last 8 h of the cycle a constant decrease in the amount of calmodulin mRNA was observed. Th e synthesis of the protein followed the expression pattern of the mRNA , but without the final decrease, The average amounts of calmodulin me asured were 2.5+/-0.9 ng/10(8) 14-h-old rings, 4.38+/-0.35 ng/10(8) 36 -h-old trophozoites, 11.8+/-1.45 ng/10(8) 44-h-old trophozoites, and 1 9.6+/-1.9 ng/10(8) 48-h-old schizonts. The in vivo stability of mRNA i n different developmental stages was evaluated by pulse and chase expe riments. The RNA of very mature trophozoites was quickly degraded, in contrast with the high stability shown by the RNA in other stages, The results here suggest that the calmodulin gene expression in Plasmodiu m does not follow a housekeeping pattern of expression such as in othe r eukaryotic cells, but that it is regulated at the level of transcrip tion and RNA degradation.