Tisp40, a spermatid specific bZip transcription factor, functions by binding to the unfolded protein response element via the Rip pathway

Genes Cells. 2005 Jun;10(6):575-94. doi: 10.1111/j.1365-2443.2005.00860.x.

Abstract

TISP40, a mouse spermatid-specific gene, encodes a CREB/CREM family transcription factor that is predominantly expressed during spermiogenesis. We report here that TISP40 generates two types of proteins, Tisp40alpha and Tisp40beta, both of which contain a transmembrane domain and localize to the endoplasmic reticulum (ER). In contrast, mutant proteins lacking the transmembrane domain (Tisp40alpha/betaDeltaTM) primarily localize to the nucleus. Endoglycosidase H treatment shows that the C-terminus of Tisp40alpha/beta is glycosylated. Protease experiments demonstrate that Tisp40alpha/beta are Type II transmembrane proteins that are released into the nucleus by a two-step cleavage mechanism called 'regulated intramembrane proteolysis' (Rip). Unlike previously published observations, Tisp40alpha does not bind to the NF-kappaB site; instead, it specifically binds to the unfolded protein response element (UPRE). Luciferase assays reveal that Tisp40betaDeltaTM activates transcription through UPRE. Northern blot analysis shows that Tisp40alpha/betaDeltaTM proteins up-regulate EDEM (ER degradation of enhancing alpha-manosidase-like protein) mRNA. These observations unveil a novel event in mouse spermiogenesis and show that the final stage of transcriptional regulation is controlled by the Rip pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites / drug effects
  • Cell Line
  • Cell Nucleus / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Electrophoretic Mobility Shift Assay
  • Endoplasmic Reticulum / metabolism
  • Gene Expression Regulation / drug effects
  • Glycoside Hydrolases / pharmacology*
  • Glycosylation
  • HeLa Cells
  • Histidine / chemistry
  • Humans
  • Kidney / cytology
  • Kidney / embryology
  • Leucine Zippers
  • Luciferases / metabolism
  • Male
  • Mice
  • Molecular Sequence Data
  • Phosphorylation
  • Phylogeny
  • Protein Binding / drug effects
  • Protein Processing, Post-Translational
  • Protein Structure, Tertiary
  • Proteins / metabolism*
  • RNA, Messenger / metabolism
  • Receptor-Interacting Protein Serine-Threonine Kinases
  • Response Elements / genetics*
  • Sequence Deletion
  • Spermatids / metabolism*
  • Spermatogenesis
  • Transcription Factors / chemistry
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism*

Substances

  • DNA-Binding Proteins
  • Proteins
  • RNA, Messenger
  • Transcription Factors
  • Histidine
  • Luciferases
  • RIPK1 protein, human
  • Receptor-Interacting Protein Serine-Threonine Kinases
  • Ripk1 protein, mouse
  • Glycoside Hydrolases