Related Experiment Video

Updated: Jul 19, 2026

Indirect Immunofluorescence on Frozen Sections of Mouse Mammary Gland
11:13

Indirect Immunofluorescence on Frozen Sections of Mouse Mammary Gland

Published on: December 1, 2015

Differentiation-induced cleavage of Cutl1/CDP generates a novel dominant-negative isoform that regulates mammary gene

Urmila Maitra1, Jin Seo, Mary M Lozano

  • 1Section of Molecular Genetics and Microbiology, The University of Texas at Austin, 24th and Speedway, ESB 226, Austin, TX 78712-0162, USA.

Molecular and Cellular Biology
|October 4, 2006
PubMed

Insights

A novel posttranslational process activates Cutl1/CCAAT displacement protein (CDP) during mammary gland development. This process generates a dominant-negative form, CDP150, which enhances mammary-specific gene expression.

Area of Science:

  • Molecular Biology
  • Developmental Biology
  • Gene Regulation

Background:

  • Cutl1/CCAAT displacement protein (CDP) is a transcriptional repressor regulating mouse mammary tumor virus (MMTV) transcription.
  • Full-length CDP (200 kDa) represses MMTV in virgin mammary glands by binding to negative regulatory elements (NREs).

Purpose of the Study:

  • To investigate the developmental regulation of Cutl1/CDP activity in the mammary gland.
  • To elucidate the mechanism controlling CDP's transcriptional repressor function during mammary gland differentiation.

Main Methods:

  • Western blotting of mammary tissue and SCp2 cell nuclear extracts.
  • Transfection of tagged full-length and mutant CDP cDNAs into SCp2 cells.
  • Cysteine protease inhibitor treatment and analysis of NRE binding activity.

Main Results:

  • During pregnancy, full-length CDP levels decrease, and a 150-kDa form (CDP150) appears, correlating with reduced NRE binding and increased MMTV transcription.
  • CDP150 lacks the C terminus and is generated by proteolytic cleavage within the homeodomain during differentiation.
  • Loss of CDP DNA-binding activity correlates with increased MMTV and other mammary-specific gene expression.

Conclusions:

  • A novel posttranslational proteolytic processing of Cutl1/CDP generates a dominant-negative protein (CDP150) during mammary gland development.
  • This process regulates mammary-specific gene expression by altering CDP's DNA-binding activity.
  • The findings reveal a new mechanism controlling gene expression through protein modification in development.

More Related Videos

Differentiation of Mouse Breast Epithelial HC11 and EpH4 Cells09:32

Differentiation of Mouse Breast Epithelial HC11 and EpH4 Cells

Published on: February 27, 2020

Inducible and Reversible Dominant-negative (DN) Protein Inhibition08:35

Inducible and Reversible Dominant-negative (DN) Protein Inhibition

Published on: January 7, 2019

Related Concept Videos

Genomic Imprinting and Inheritance02:30

Genomic Imprinting and Inheritance

Diploid organisms inherit genetic material through chromosomes from both parents. Copies of the same gene are known as alleles. In most cases, both alleles are simultaneously expressed and allow various cellular processes to function optimally. If one of the alleles is missing or mutated, the expression of the other allele can compensate; however, this is not true for all genes.
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
Master Transcription Regulators02:23

Master Transcription Regulators

Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a  complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
Notch Signaling Pathway03:14

Notch Signaling Pathway

The Notch signaling pathway is a major intracellular signaling pathway that is highly conserved over a broad spectrum of metazoan species. It stands unique from other intracellular signaling mechanisms in animals because notch protein itself acts as the receptor as well as the primary signaling molecule.
The Notch gene came into the limelight in 1914 after the discovery that its mutation in Drosophila melanogaster leads to a serrated (or "notched") wing margin phenotype. It was not until 1985...
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
Hedgehog Signaling Pathway02:33

Hedgehog Signaling Pathway

The Hedgehog gene (Hh) was first discovered due to its control of the growth of disorganized, hair-like bristles phenotype in Drosophila, much like hedgehog spines. Hh plays a crucial role in the development of organs and the maintenance of homeostasis in both invertebrates and vertebrates. However, while Drosophila has only one Hh protein, mammals have multiple functional Hedgehog proteins - Sonic (Shh), Desert (Dhh), and Indian Hedgehog (Ihh). All of these homologous proteins have adapted to...
Forced Transdifferentiation01:28

Forced Transdifferentiation

Transdifferentiation, also known as lineage reprogramming, was first discovered by Selman and Kafatos in 1974 in silkmoths. They observed that the moths’ cuticle-producing cells transformed into salt-producing cells. Many such cases of natural transdifferentiation occur in organisms. In humans, pancreatic alpha cells can become beta cells. In newts, the loss of the eye’s lens causes the pigmented epithelial cells to transdifferentiate into the lens cells.
Artificial transdifferentiation occurs...