Leishmania infantum Asparagine Synthetase A Is Dispensable for Parasites Survival and Infectivity

• Type: Article in International Scientific Journal
• Date: 2016

Authors

Faria, J (Author) Other; Loureiro, I (Author) Other; Santarem, N (Author) Other; Macedo Ribeiro, S (Author) Other; Tavares, J (Author) Other; Anabela Cordeiro da Silva (Author) FFUP

Journal

Title: PLoS Neglected Tropical Diseases

Vol. 10

Final page: e0004365

ISSN: 1935-2727

Publisher: Public Library of Science

Indexing

ISI Web of Knowledge - 6 Citations

Scopus - 8 Citations

Other information

Authenticus ID: P-00K-CGJ

DOI: 10.1371/journal.pntd.0004365

Abstract (EN): A growing interest in asparagine (Asn) metabolism has currently been observed in cancer and infection fields. Asparagine synthetase (AS) is responsible for the conversion of aspartate into Asn in an ATP-dependent manner, using ammonia or glutamine as a nitrogen source. There are two structurally distinct AS: the strictly ammonia dependent, type A, and the type B, which preferably uses glutamine. Absent in humans and present in trypanosomatids, AS-A was worthy of exploring as a potential drug target candidate. Appealingly, it was reported that AS-A was essential in Leishmania donovani, making it a promising drug target. In the work herein we demonstrate that Leishmania infantum AS-A, similarly to Trypanosoma spp. and L. donovani, is able to use both ammonia and glutamine as nitrogen donors. Moreover, we have successfully generated LiASA null mutants by targeted gene replacement in L. infantum, and these parasites do not display any significant growth or infectivity defect. Indeed, a severe impairment of in vitro growth was only observed when null mutants were cultured in asparagine limiting conditions. Altogether our results demonstrate that despite being important under asparagine limitation, LiAS-A is not essential for parasite survival, growth or infectivity in normal in vitro and in vivo conditions. Therefore we exclude AS-A as a suitable drug target against L. infantum parasites.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 22