title: Calcium signaling in trypanosomatid parasites.
abstract: Calcium ion (Ca(2+)) is an important second messenger in trypanosomatids and essential for their survival although prolonged high intracellular Ca(2+) levels lead to cell death. As other eukaryotic cells, trypanosomes use two sources of Ca(2+) for generating signals: Ca(2+) release from intracellular stores and Ca(2+) entry across the plasma membrane. Ca(2+) release from intracellular stores is controlled by the inositol 1,4,5-trisphosphate receptor (IP3R) that is located in acidocalcisomes, acidic organelles that are the primary Ca(2+) reservoir in these cells. A plasma membrane Ca(2+)-ATPase controls the cytosolic Ca(2+) levels and a number of pumps and exchangers are responsible for Ca(2+) uptake and release from intracellular compartments. The trypanosomatid genomes contain a wide variety of signaling and regulatory proteins that bind Ca(2+) as well as many Ca(2+)-binding proteins that await further characterization. The mitochondrial Ca(2+) transporters of trypanosomatids have an important role in the regulation of cell bioenergetics and flagellar Ca(2+) appears to have roles in sensing the environment. In trypanosomatids in which an intracellular life cycle is present, Ca(2+) signaling is important for host cell invasion.
authors.affiliation: Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, GA 30620, USA; Departamento de Patologia Clínica, State University of Campinas, Campinas, SP 13083, Brazil. Electronic address: rdocampo@uga.edu.
authors.forename: Roberto
authors.initials: R
authors.lastname: Docampo
authors.affiliation: Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, GA 30620, USA.
authors.forename: Guozhong
authors.initials: G
authors.lastname: Huang
mesh_terms: D000818:Animals; D020013:Calcium Signaling / Q000502:physiology*; D006801:Humans; D010271:Parasites / Q000378:metabolism*; D014345:Trypanosoma / Q000378:metabolism*
keywords: Acidic store; Acidocalcisome; Calcium; Inositol 1,4,5-trisphosphate receptor; Leishmania; Trypanosoma