Identification of a shootin1 isoform expressed in peripheral tissues

Cell Tissue Res. 2016 Oct;366(1):75-87. doi: 10.1007/s00441-016-2415-9. Epub 2016 May 13.


Shootin1 is a brain-specific cytoplasmic protein involved in neuronal polarity formation and axon outgrowth. It accumulates at the leading edge of axonal growth cones, where it mediates the mechanical coupling between F-actin retrograde flow and cell adhesions as a clutch molecule, thereby producing force for axon outgrowth. In this study, we report a novel splicing isoform of shootin1 which is expressed not only in the brain but also in peripheral tissues. We have renamed the brain-specific shootin1 as shootin1a and termed the novel isoform as shootin1b. Immunoblot and immunohistochemical analyses with a shootin1b-specific antibody revealed that shootin1b is distributed in various mouse tissues including the lung, liver, stomach, intestines, spleen, pancreas, kidney and skin. Interestingly, shootin1b immunoreactivity was widely detected in epithelial cells that constitute simple and stratified epithelia; in some cells, it colocalized with E-cadherin and cortactin at cell-cell contact sites. Shootin1b also localized in dendritic cells in the spleen. These results suggest that shootin1b may function in various peripheral tissues including epithelial cells.

Keywords: Clutch molecule; Dendritic cell; Epithelial cell; Shootin1b.

MeSH terms

  • Aging / metabolism
  • Amino Acid Sequence
  • Animals
  • Antibody Specificity
  • Cadherins / metabolism
  • Cell Communication
  • Cortactin / metabolism
  • Immunohistochemistry
  • Mice, Inbred C57BL
  • Nerve Tissue Proteins / chemistry
  • Nerve Tissue Proteins / metabolism*
  • Organ Specificity*
  • Protein Isoforms
  • Protein Transport
  • Rats
  • Tissue Distribution


  • Cadherins
  • Cortactin
  • Nerve Tissue Proteins
  • Protein Isoforms
  • Shtn1 protein, rat