Article

Mitochondrial Associated Ubiquitin Fold Modifier-1 Mediated Protein Conjugation in Leishmania donovani

Louisiana State University, United States of America
PLoS ONE (Impact Factor: 3.53). 01/2011; 6(1):e16156. DOI: 10.1371/journal.pone.0016156
Source: PubMed

ABSTRACT In this report, we demonstrate the existence of the ubiquitin fold modifier-1 (Ufm1) and its conjugation pathway in trypanosomatid parasite Leishmania donovani. LdUfm1 is activated by E1-like enzyme LdUba5. LdUfc1 (E2) specifically interacted with LdUfm1 and LdUba5 to conjugate LdUfm1 to proteinaceous targets. Mass spectrometry analysis revealed that LdUfm1 is conjugated to Leishmania protein targets that are associated with mitochondria. Immunofluorescence experiments showed that Leishmania Ufm1, Uba5 and Ufc1 are associated with the mitochondria. The demonstration that all the components of this system as well as the substrates are associated with mitochondrion suggests it may have physiological roles not yet described in any other organism. Overexpression of a non-conjugatable form of LdUfm1 and an active site mutant of LdUba5 resulted in reduced survival of Leishmania in the macrophage. Since mitochondrial activities are developmentally regulated in the life cycle of trypanosomatids, Ufm1 mediated modifications of mitochondrial proteins may be important in such regulation. Thus, Ufm1 conjugation pathway in Leishmania could be explored as a potential drug target in the control of Leishmaniasis.

0 Followers
 · 
106 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The ubiquitin-fold modifier 1 (Ufm1) is a posttranslational modifier that belongs to the ubiquitin-like protein (UBL) family. Ufm1 is present in nearly all eukaryotic organisms, with the exception of fungi. It resembles ubiquitin in its ability to be ligated to other proteins, as well as in the mechanism of ligation. While the Ufm1 cascade has been implicated in endoplasmic reticulum functions and cell cycle control, its biological role still remains poorly understood. In this short review, we summarize the current state of Ufm1 research and its potential role in human diseases, like diabetes, ischemic heart disease and cancer.
    06/2014; 3(2):627-638. DOI:10.3390/cells3020627
  • [Show abstract] [Hide abstract]
    ABSTRACT: Uba5 is the smallest ubiquitin-like molecule-activating enzyme and contains an adenylation domain and a C-terminal region. This enzyme only exists in multicellular organisms. The mechanism through which the enzyme recognizes and activates ubiquitin-fold modifier 1 (Ufm1) remains unknown. In this study, Uba5 adenylation domains with different C-terminal region lengths were cloned, expressed and purified. The results of an in vitro truncation assay suggest that Uba5 residues 57-363 comprise the minimal fragment required for the high-efficiency activation of Ufm1. Crystallization of Uba5 residues 57-363 was performed at 277 K using PEG 3350 as the precipitant, and crystals optimized by microseeding diffracted to 2.95 Å resolution, with unit-cell parameters a = b = 97.66, c = 144.83 Å, α = β = 90, γ = 120°. There is one molecule in the asymmetric unit; the Matthews coefficient and the solvent content were calculated to be 2.93 Å(3) Da(-1) and 58.1%, respectively.
    Acta Crystallographica Section F Structural Biology and Crystallization Communications 06/2014; 70(Pt 6):765-768. DOI:10.1107/S2053230X14008826 · 0.57 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Biological roles for UFM1, a ubiquitin-like protein, are largely unknown, and therefore we screened for targets of ufmylation. Here we show that ufmylation of the nuclear receptor coactivator ASC1 is a key step for ERα transactivation in response to 17β-estradiol (E2). In the absence of E2, the UFM1-specific protease UfSP2 was bound to ASC1, which maintains ASC1 in a nonufmylated state. In the presence of E2, ERα bound ASC1 and displaced UfSP2, leading to ASC1 ufmylation. Polyufmylation of ASC1 enhanced association of p300, SRC1, and ASC1 at promoters of ERα target genes. ASC1 overexpression or UfSP2 knockdown promoted ERα-mediated tumor formation in vivo, which could be abrogated by treatment with the anti-breast cancer drug tamoxifen. In contrast, expression of ufmylation-deficient ASC1 mutant or knockdown of the UFM1-activating E1 enzyme UBA5 prevented tumor growth. These findings establish a role for ASC1 ufmylation in breast cancer development by promoting ERα transactivation.
    Molecular Cell 09/2014; 56(2). DOI:10.1016/j.molcel.2014.08.007 · 14.46 Impact Factor

Full-text (3 Sources)

Download
74 Downloads
Available from
Jun 4, 2014