• Register
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.


Leaving Community

Are you sure you want to leave this community? Leaving the community will revoke any permissions you have been granted in this community.


Nuclear membrane protein LAP2beta mediates transcriptional repression alone and together with its binding partner GCL (germ-cell-less).

LAP2beta is an integral membrane protein of the nuclear envelope involved in chromatin and nuclear architecture. Using the yeast two-hybrid system, we have cloned a novel LAP2beta-binding protein, mGCL, which contains a BTB/POZ domain and is the mouse homologue of the Drosophila germ-cell-less (GCL) protein. In Drosophila embryos, GCL was shown to be essential for germ cell formation and was localized to the nuclear envelope. Here, we show that, in mammalian cells, GCL is co-localized with LAP2beta to the nuclear envelope. Nuclear fractionation studies reveal that mGCL acts as a nuclear matrix component and not as an integral protein of the nuclear envelope. Recently, mGCL was found to interact with the DP3alpha component of the E2F transcription factor. This interaction reduced the transcriptional activity of the E2F-DP heterodimer, probably by anchoring the complex to the nuclear envelope. We demonstrate here that LAP2beta is also capable of reducing the transcriptional activity of the E2F-DP complex and that it is more potent than mGCL in doing so. Co-expression of both LAP2beta and mGCL with the E2F-DP complex resulted in a reduced transcriptional activity equal to that exerted by the pRb protein.

Pubmed ID: 11591818


  • Nili E
  • Cojocaru GS
  • Kalma Y
  • Ginsberg D
  • Copeland NG
  • Gilbert DJ
  • Jenkins NA
  • Berger R
  • Shaklai S
  • Amariglio N
  • Brok-Simoni F
  • Simon AJ
  • Rechavi G


Journal of cell science

Publication Data

September 9, 2001

Associated Grants


Mesh Terms

  • Amino Acid Sequence
  • Animals
  • Carcinoma, Non-Small-Cell Lung
  • Carrier Proteins
  • Cell Cycle Proteins
  • Chromosomes
  • DNA-Binding Proteins
  • Drosophila
  • Drosophila Proteins
  • E2F Transcription Factors
  • Humans
  • Insulinoma
  • Lung Neoplasms
  • Macromolecular Substances
  • Membrane Proteins
  • Mice
  • Molecular Sequence Data
  • Nuclear Envelope
  • Nuclear Proteins
  • Pancreas
  • Protein Transport
  • Saccharomyces cerevisiae
  • Sequence Homology
  • Transcription Factors
  • Transcription, Genetic
  • Tumor Cells, Cultured