Human tra2-beta1 autoregulates its protein concentration by influencing alternative splicing of its pre-mRNA

Hum Mol Genet. 2004 Mar 1;13(5):509-24. doi: 10.1093/hmg/ddh051. Epub 2004 Jan 6.

Abstract

HTRA2-BETA1 is an SR-like protein that regulates alternative splice site selection in a concentration-dependent manner. Its proper concentration is important as several pathological states are associated with its change. We investigated the mechanism that controls the cellular HTRA2-BETA1 concentration and found it utilizes a negative feedback loop to regulate the splicing of its exon 2. TRA2-BETA1 binds to four enhancers present in exon 2, which activates its inclusion. Inclusion of exon 2 generates mRNAs that are not translated into proteins. Mutations of exon 2 enhancers demonstrate that TRA2-BETA1 binds a degenerate sequence GHVVGANR, which is found more frequently in exons than in introns. Hyperphosphorylation of TRA2-BETA1 strongly reduces its binding to RNA. Presence of the CLK2 kinase prevents the usage of exons 2 and 3, generating the htra2-beta3 mRNA. The resulting HTRA2-BETA3 protein lacks the first RS domain of HTRA2-BETA1, is expressed in several tissues and has no influence on tra2-beta splice site selection. HTRA2-BETA1 interacting proteins promote exon 2 skipping by sequestering it, which upregulates the HTRA2-BETA1 protein synthesis. We propose that the regulation of the tra2-beta pre-mRNA alternative splicing provides a robust and sensitive molecular sensor that measures the ratio between HTRA2-BETA1 and its interacting proteins.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing / genetics
  • Alternative Splicing / physiology*
  • Amino Acid Motifs
  • Blotting, Western
  • DNA Primers
  • Enhancer Elements, Genetic / genetics
  • Exons / genetics
  • Gene Expression Regulation*
  • Humans
  • Immune Sera
  • Mutagenesis, Site-Directed
  • Mutation / genetics
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Nerve Tissue Proteins / physiology
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / metabolism
  • Protein-Tyrosine Kinases
  • RNA Precursors / metabolism*
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • RNA-Binding Proteins / physiology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Serine-Arginine Splicing Factors
  • Transfection

Substances

  • DNA Primers
  • Immune Sera
  • Nerve Tissue Proteins
  • RNA Precursors
  • RNA-Binding Proteins
  • TRA2B protein, human
  • Serine-Arginine Splicing Factors
  • Clk dual-specificity kinases
  • Protein-Tyrosine Kinases
  • Protein-Serine-Threonine Kinases