An upstream open reading frame regulates LST1 expression during monocyte differentiation

Christian Schiller; Carina Nowak; Kalliope N Diakopoulos; Ulrich H Weidle; Elisabeth H Weiss

doi:10.1371/journal.pone.0096245

An upstream open reading frame regulates LST1 expression during monocyte differentiation

PLoS One. 2014 May 9;9(5):e96245. doi: 10.1371/journal.pone.0096245. eCollection 2014.

Authors

Christian Schiller¹, Carina Nowak¹, Kalliope N Diakopoulos¹, Ulrich H Weidle², Elisabeth H Weiss¹

Affiliations

¹ Department of Biology II, Ludwig-Maximilians-Universität München, Germany.
² Division Pharma, Roche Diagnostics, Penzberg, Germany.

Abstract

The regulation of gene expression depends on the interplay of multiple factors at the transcriptional and translational level. Upstream open reading frames (uORFs) play an important role as translational repressors of main ORFs and their presence or usage in transcripts can be regulated by different mechanisms. The main objective of the present study was to assess whether uORFs regulate the expression of the MHC class III gene LST1. We report that expression of LST1 is tightly regulated by alternative transcription initiation and the presence of an uORF in the 5'-UTR of transcripts. Specifically, using EGFP reporter constructs in human HeLa and HEK-293T cells and flow cytometry as well as western blot analysis we found the uORF to reduce the expression of the main ORF by roughly two-thirds. Furthermore, we were able to correlate a previously detected increase in LST1 protein expression during monocyte differentiation with an increase of transcription initiation at an alternative exon that does not contain an uORF.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

5' Untranslated Regions / genetics*
Amino Acid Sequence
Base Sequence
Blotting, Western
Cell Differentiation / genetics*
Cell Line, Tumor
Flow Cytometry
Gene Expression Regulation*
Green Fluorescent Proteins / genetics
Green Fluorescent Proteins / metabolism
HEK293 Cells
HeLa Cells
Humans
Intracellular Signaling Peptides and Proteins
Major Histocompatibility Complex / genetics
Membrane Proteins / genetics*
Membrane Proteins / metabolism
Molecular Sequence Data
Monocytes / cytology
Monocytes / metabolism*
Open Reading Frames / genetics*
Reverse Transcriptase Polymerase Chain Reaction
Sequence Homology, Amino Acid
Sequence Homology, Nucleic Acid
Transcription Initiation, Genetic
U937 Cells

Substances

5' Untranslated Regions
Intracellular Signaling Peptides and Proteins
LST1 protein, human
Membrane Proteins
Green Fluorescent Proteins

Grants and funding

This work was supported by the Helmholtz Zentrum München PhD Program, Research Field “Infection and Immunity”. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.