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L eishmania donovani ‐specific U b‐related modifier‐1: an early endosome‐associated ubiquitin‐like conjugation in L eishmania donovani
Author(s) -
Sharma Vanila,
Sharma Paresh,
Selvapandiyan Angamuthu,
Salotra Poonam
Publication year - 2016
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.13253
Subject(s) - biology , endosome , microbiology and biotechnology , ubiquitin , leishmania donovani , endocytosis , biochemistry , amastigote , leishmania , genetics , cell , gene , visceral leishmaniasis , leishmaniasis , parasite hosting , world wide web , computer science
Summary Protein modification by ubiquitin ( U b) and U b‐like molecules ( U bls) is a diverse biological process that regulates the activity of the target proteins. Systematic studies of U bls in trypanosomatids like L eishmania , the causative organism of potentially fatal visceral leishmaniasis, would yield a better understanding of the disease pathogenesis and identify novel therapeutic targets. The present study is the first to characterize L eishmania donovani ‐specific U b‐related modifier‐1 ( LdU rm1) and the associated conjugation pathway. Based on homology modeling, LdUrm1 was found to possess a β‐grasp fold and a C ‐terminal di‐glycine motif unique to U b/ U bls, essential for its conjugation to the target proteins. We identified LdU ba4 as the E 1 enzyme for LdU rm1 and demonstrated its energy‐dependent enzymatic activity. LdUrm1 was immunolocalized anteriorly near the flagellar reservoir, while LdUba4 was cytoplasmic, both in promastigotes and axenic amastigotes. Expression of nonconjugatable LdU rm1 in L . donovani resulted in depleted parasite growth suggesting its role in the pathogenesis. By mass spectrometry, we identified R ab5, a known mediator of early endosome regulated hemoglobin endocytosis in L eishmania , as a target of LdU rm1. Our data suggest that LdU rm1 conjugation pathway may have a role in early endosome‐mediated heme uptake in L eishmania that may be explored as a drug target.