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Identification of a Developmentally Regulated Calcium‐Binding Protein in Trypanosoma brucei 1
Author(s) -
Ruben Larry
Publication year - 1987
Publication title -
the journal of protozoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 0022-3921
DOI - 10.1111/j.1550-7408.1987.tb03193.x
Subject(s) - calcium , calcium binding protein , biochemistry , trypanosoma brucei , calmodulin , cytosol , biology , binding protein , dna binding protein , plasma protein binding , microbiology and biotechnology , chemistry , enzyme , organic chemistry , gene , transcription factor
ABSTRACT Calcium ions mediate cellular activity by binding to specific cellular proteins. The following study systematically examines the cellular complement of calcium‐binding proteins in different cell fractions and life cycle stages of Trypanosoma brucei. Using a 45 Ca‐gel overlay procedure, eight calcium‐binding proteins were consistently observed. The majority of proteins were cytosolic (84, 70, 64, 22, and 15 kd) while the remainder (55, 46, and 29 kd) were particulate. Although calmodulin was detected amongst the calcium‐binding proteins, it did not represent the majority of calcium‐binding activity. Of special interest was the 46 kd calcium‐binding protein which was associated with 3‐fold more calcium in cultured procyclic forms than in slender bloodstream forms. By contrast, promastigote forms of Leishmania mexicana did not contain the 46 kd calcium‐binding protein. These data suggest that responsiveness to calcium signals may vary during the trypanosome life cycle as a result of changes in the cellular complement of calcium‐binding proteins.