The splicing regulator PTBP1 controls the activity of the transcription factor Pbx1 during neuronal differentiation

Elife. 2015 Dec 24;4:e09268. doi: 10.7554/eLife.09268.

Abstract

The RNA-binding proteins PTBP1 and PTBP2 control programs of alternative splicing during neuronal development. PTBP2 was found to maintain embryonic splicing patterns of many synaptic and cytoskeletal proteins during differentiation of neuronal progenitor cells (NPCs) into early neurons. However, the role of the earlier PTBP1 program in embryonic stem cells (ESCs) and NPCs was not clear. We show that PTBP1 controls a program of neuronal gene expression that includes the transcription factor Pbx1. We identify exons specifically regulated by PTBP1 and not PTBP2 as mouse ESCs differentiate into NPCs. We find that PTBP1 represses Pbx1 exon 7 and the expression of the neuronal Pbx1a isoform in ESCs. Using CRISPR-Cas9 to delete regulatory elements for exon 7, we induce Pbx1a expression in ESCs, finding that this activates transcription of neuronal genes. Thus, PTBP1 controls the activity of Pbx1 to suppress its neuronal transcriptional program prior to induction of NPC development.

Keywords: RNA binding protein; alternative splicing; chromosomes; developmental biology; embryonic stem cells; genes; mouse; posttranscriptional regulation; stem cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation*
  • Embryonic Stem Cells / physiology*
  • Gene Expression Regulation
  • Heterogeneous-Nuclear Ribonucleoproteins / metabolism*
  • Homeodomain Proteins / metabolism*
  • Mice
  • Neurons / physiology*
  • Polypyrimidine Tract-Binding Protein / metabolism*
  • Pre-B-Cell Leukemia Transcription Factor 1
  • Transcription Factors / metabolism*

Substances

  • Heterogeneous-Nuclear Ribonucleoproteins
  • Homeodomain Proteins
  • Pbx1 protein, mouse
  • Pre-B-Cell Leukemia Transcription Factor 1
  • Ptbp1 protein, mouse
  • Transcription Factors
  • Polypyrimidine Tract-Binding Protein