The Histidine Ammonia Lyase of Trypanosoma cruzi Is Involved in Acidocalcisome Alkalinization and Is Essential for Survival under Starvation Conditions.

ABSTRACT: Trypanosoma cruzi, the agent of Chagas disease, accumulates polyphosphate (polyP) and Ca²⁺ inside acidocalcisomes. The alkalinization of this organelle stimulates polyP hydrolysis and Ca²⁺ release. Here, we report that histidine ammonia lyase (HAL), an enzyme that catalyzes histidine deamination with production of ammonia (NH₃) and urocanate, is responsible for acidocalcisome alkalinization. Histidine addition to live parasites expressing HAL fused to the pH-sensitive emission biosensor green fluorescent protein (GFP) variant pHluorin induced alkalinization of acidocalcisomes. PolyP decreased HAL activity of epimastigote lysates or the recombinant protein but did not cause its polyphosphorylation, as determined by the lack of HAL electrophoretic shift on Nu

SUBMITTER: Mantilla BS 

PROVIDER: S-EPMC8561398 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature