Expression of the cyclin-dependent kinase inhibitor p27Kip1 by developing retinal pigment epithelium

Gene Expr Patterns. 2003 Oct;3(5):615-9. doi: 10.1016/s1567-133x(03)00120-0.


The cyclin-dependent kinase (Cdk) inhibitor p27Kip1 contributes to the timing of cell cycle withdrawal during development and, consequently, in organogenesis. Within the retina, this effector protein is up-regulated during the birth of neuronal and glial cells [Dev. Biol. (2000) 299]. However, its expression within the retinal pigment epithelium (RPE), a supporting cell layer that is essential for neural retina development and function, has not previously been reported. We show that p27Kip1 protein expression in the RPE occurs in two phases: an up-regulation during mid-to late embryonic stages and a down-regulation during the subsequent postnatal period. In the early phase of up-regulation, an inverse relationship is seen between expression of p27Kip1 and PCNA, an indicator of cycling cells. During both up-and down-regulation, the change in spatial pattern of expression proceeds in a central to peripheral manner, with p27Kip1 up-regulation paralleling retinal maturation. These data suggest that this cell cycle regulator may be an important factor controlling the timing of RPE cell cycle withdrawal.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Cycle Proteins / metabolism*
  • Cell Division
  • Cyclin-Dependent Kinase Inhibitor p27
  • Enzyme Inhibitors / metabolism
  • Pigment Epithelium of Eye / embryology*
  • Pigment Epithelium of Eye / metabolism*
  • Rats
  • Tumor Suppressor Proteins / metabolism*


  • Cdkn1b protein, rat
  • Cell Cycle Proteins
  • Enzyme Inhibitors
  • Tumor Suppressor Proteins
  • Cyclin-Dependent Kinase Inhibitor p27