SH3GL3 Associates With the Huntingtin Exon 1 Protein and Promotes the Formation of Polygln-Containing Protein Aggregates

Mol Cell. 1998 Oct;2(4):427-36. doi: 10.1016/s1097-2765(00)80142-2.

Abstract

The mechanism by which aggregated polygins cause the selective neurodegeneration in Huntington's disease (HD) is unknown. Here, we show that the SH3GL3 protein, which is preferentially expressed in brain and testis, selectively interacts with the HD exon 1 protein (HDex1p) containing a glutamine repeat in the pathological range and promotes the formation of insoluble polyglutamine-containing aggregates in vivo. The C-terminal SH3 domain in SH3GL3 and the proline-rich region in HDex1p are essential for the interaction. Coimmunoprecipitations and immunofluorescence studies revealed that SH3GL3 and HDex1p colocalize in transfected COS cells. Additionally, an anti-SH3GL3 antibody was also able to coimmunoprecipitate the full-length huntingtin from an HD human brain extract. The characteristics of the interaction between SH3GL3 and huntingtin and the colocalization of the two proteins suggest that SH3GL3 could be involved in the selective neuronal cell death in HD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Animals
  • Brain Chemistry
  • COS Cells
  • Carrier Proteins / genetics*
  • Carrier Proteins / isolation & purification
  • Carrier Proteins / metabolism*
  • Exons / genetics
  • Gene Expression
  • Glutamine / genetics*
  • Glutamine / metabolism
  • Humans
  • Huntingtin Protein
  • Huntington Disease / genetics*
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / isolation & purification
  • Nerve Tissue Proteins / metabolism
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / isolation & purification
  • Nuclear Proteins / metabolism
  • Peptide Fragments / genetics
  • Peptide Fragments / metabolism
  • Precipitin Tests
  • Proline
  • RNA, Messenger / analysis
  • Rabbits
  • Repetitive Sequences, Nucleic Acid
  • Subcellular Fractions / chemistry
  • Yeasts / genetics
  • src Homology Domains / genetics*

Substances

  • Adaptor Proteins, Signal Transducing
  • Carrier Proteins
  • HTT protein, human
  • Huntingtin Protein
  • Nerve Tissue Proteins
  • Nuclear Proteins
  • Peptide Fragments
  • RNA, Messenger
  • SH3GL3 protein, human
  • Glutamine
  • Proline