Next Article in Journal
Efficient Delivery of Macromolecules into Human Cells by Improving the Endosomal Escape Activity of Cell-Penetrating Peptides: Lessons Learned from dfTAT and its Analogs
Next Article in Special Issue
Crystal Structure of the Human tRNA Guanine Transglycosylase Catalytic Subunit QTRT1
Previous Article in Journal
A Novel Cell Penetrating Peptide for the Differentiation of Human Neural Stem Cells
Previous Article in Special Issue
tRNA Modification Detection Using Graphene Nanopores: A Simulation Study
Article Menu
Issue 3 (September) cover image

Export Article

Open AccessArticle
Biomolecules 2018, 8(3), 49; https://doi.org/10.3390/biom8030049

Protein Phosphatase Sit4 Affects Lipid Droplet Synthesis and Soraphen A Resistance Independent of Its Role in Regulating Elongator Dependent tRNA Modification

1
Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
2
Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, 34132 Kassel, Germany
*
Authors to whom correspondence should be addressed.
Received: 4 June 2018 / Revised: 5 July 2018 / Accepted: 9 July 2018 / Published: 11 July 2018
(This article belongs to the Collection RNA Modifications)
Full-Text   |   PDF [4118 KB, uploaded 11 July 2018]   |  

Abstract

The protein phosphatase Sit4 has been shown to be required for lipogenesis and resistance against the acetyl-CoA carboxylase inhibitor soraphen A. Since Sit4 is also required for biosynthesis of Elongator dependent tRNA modifications such as 5-methoxycarbonylmethyluridine (mcm5U), we investigated the relevance of tRNA modifications in lipogenesis and soraphen A response. While sit4 and Elongator (elp3) mutants copy defects in mcm5U formation and stress sensitivity, they do not share soraphen A sensitivity and low lipid droplet (LD) phenotypes. In contrast to sit4, we found elp3 mutants to display partial soraphen A resistance and a high LD phenotype. Screening a collection of tRNA modification mutants additionally identified the tRNA pseudo-uridine synthase gene DEG1 to be required for soraphen A sensitivity. Since deg1 and elp3 share high LD and soraphen A resistance phenotypes, these are likely caused by translational defects. In support of this notion, we observe overexpression of tRNAGlnUUG suppresses lipolysis defects of deg1 mutants. Hence, the sit4 mutation results in a composite defect including tRNA modification deficiency and loss of Snf1 kinase dephosphorylation, which induce opposite effects on LD regulation. Importantly, however, the Snf1 kinase regulatory defects of the phosphatase mutant dominate over effects on LD regulation imposed by loss of the tRNA modification alone. View Full-Text
Keywords: soraphen A; Sit4; tRNA modification; Elongator complex soraphen A; Sit4; tRNA modification; Elongator complex
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Bozaquel-Morais, B.L.; Vogt, L.; D’Angelo, V.; Schaffrath, R.; Klassen, R.; Montero-Lomelí, M. Protein Phosphatase Sit4 Affects Lipid Droplet Synthesis and Soraphen A Resistance Independent of Its Role in Regulating Elongator Dependent tRNA Modification. Biomolecules 2018, 8, 49.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Biomolecules EISSN 2218-273X Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top