CTCF

1. 본문

CTCF (CCCTC-binding factor) is a protein encoded by the *CTCF* gene in humans. It's a highly versatile transcription factor involved in a wide array of cellular processes. Here's a breakdown of its key aspects:
Function:

• Chromatin Architecture Regulation: CTCF's primary role is regulating the 3D structure of chromatin. It achieves this by:
• Binding together DNA strands to form chromatin loops.
• Anchoring DNA to cellular structures (e.g., the nuclear lamina).
• Defining boundaries between active and heterochromatic (inactive) DNA regions.
• Transcriptional Regulation: Because the 3D structure of DNA impacts gene regulation, CTCF's activity influences gene expression. It can act as both an activator and a repressor of transcription.
• Insulator Activity: CTCF is the main insulator protein in vertebrates. Insulators:
• Block interaction between enhancers (DNA sequences that increase transcription) and promoters (DNA sequences where transcription starts).
• Limit enhancer activity to specific functional domains.
• Can buffer transgenes from chromosomal position effects.
• Other Roles:
• Regulation of RNA splicing.
• V(D)J recombination (a process that generates diversity in immune cells).
• Genomic imprinting (influencing gene expression based on parent-of-origin).
• X-chromosome inactivation

• Zinc Fingers: CTCF has 11 zinc finger domains, allowing it to bind to a wide variety of DNA sequences with different combinations of these fingers.
• Dimerization: CTCF can bind to itself (homodimerization), which is crucial for forming DNA loops.
• Cohesin Interaction: CTCF often works with the cohesin protein complex, which also plays a significant role in chromosome structure and organization, supporting the DNA looping.

• Development and Reproduction: CTCF plays a crucial role in development, reproduction, and genomic imprinting.
• Disease Association: Aberrant CTCF function is associated with several diseases, including some intellectual developmental disorders, and cancers.
• Assisted Reproductive Technologies (ART): The methylation patterns of CTCF binding sites can influence fertility and the success of ARTs.