AUTHOR=Azevedo Clênia S. , Guido Bruna C. , Pereira Jhonata L. , Nolasco Diego O. , Corrêa Rafael , Magalhães Kelly G. , Motta Flávia N. , Santana Jaime M. , Grellier Philippe , Bastos Izabela M. D. 

TITLE=Revealing a Novel Otubain-Like Enzyme from Leishmania infantum with Deubiquitinating Activity toward K48-Linked Substrate

JOURNAL=Frontiers in Chemistry

VOLUME=Volume 5 - 2017

YEAR=2017

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2017.00013

DOI=10.3389/fchem.2017.00013

ISSN=2296-2646

ABSTRACT=Deubiquitinating enzymes (DUBs) play an important role in regulating a variety of eukaryotic processes. In this context, exploring the role of deubiquitination in Leishmania infantum could be a promising alternative to search new therapeutic targets for leishmaniasis. Here we present the first characterization of a DUB from L. infantum, otubain (OtuLi), and its localization within parasite. The recombinant OtuLi (rOtuLi) showed improved activity on lysine 48 (K48)-linked over K63-linked tetra-ubiquitin (Ub) and site-directed mutations on amino acids close to the catalytic site (F82) or involved in Ub interaction (L265 and F182) caused structural changes as shown by molecular dynamics, resulting in a reduction or loss of enzyme activity, respectively. Furthermore, rOtuLi stimulates lipid droplet biogenesis (an inflammatory marker) in peritoneal macrophages and induces IL-6 and TNF-α secretion in peritoneal macrophages, both proinflammatory cytokines. Our findings suggest that OtuLi is a cytoplasmic enzyme with K48-linked substrate specificity that could play a part in proinflammatory response in stimulated murine macrophages.