Related Experiment Video
Updated: Jan 30, 2026
10:16
Promoter Capture Hi-C: High-resolution, Genome-wide Profiling of Promoter Interactions
Published on: June 28, 2018
33.4K
PAX-Interacting Protein 1 (PTIP) Promotes Apoptosis
Ching-Jung Huang1, Hyein Cho2, Chuan Li3
1Department of Biology, Arts and Sciences, New York University in Shanghai, Shanghai 200122, China.
Journal of Cellular Signaling
|January 29, 2026
Summary
PAX-interacting protein 1 (PTIP) can move from the nucleus to mitochondria, causing cell death. Specific regions of PTIP are crucial for this mitochondrial apoptosis and its cell cycle role.
Area of Science:
- Molecular Biology
- Cell Biology
- Genetics
Background:
- PAX-interacting protein 1 (PTIP/PAXIP1) is a protein with six BRCT repeats.
- PTIP is involved in DNA damage repair, histone methylation, and VDJ/CSR in the hematopoietic lineage.
Purpose of the Study:
- To investigate the novel role of PTIP in cellular apoptosis.
- To identify the mechanism by which PTIP induces apoptosis.
Main Methods:
- Investigated PTIP localization and function using cell-based assays.
- Examined the impact of PTIP deletion or mutation on apoptosis and cell cycle progression.
Main Results:
- A fraction of PTIP translocates from the nucleus to mitochondria, leading to mitochondrial aggregation and apoptosis.
- Deletion of the N-terminal glutamine-rich region, mutation in BRCT3, or truncation of BRCT5 domain reduced PTIP-induced apoptosis.
- These modifications also affected PTIP's previously known G2/M cell cycle function.
Conclusions:
- PTIP utilizes a mitochondrial-dependent apoptotic pathway.
- Specific domains of PTIP are critical for both its apoptotic function and its role in cell cycle regulation.
Related Concept Videos
01:30Apoptosis
14.4K
Apoptosis is a combination of two Greek words, 'apo' and 'ptosis,' meaning separation and falling off, respectively. Hippocrates used this word to describe gangrene, which was caused due to bandaging of fractured bones. Apoptosis was distinguished from necrosis in 1970 when John Kerr reported observations of morphological changes occurring during apoptosis. During one experiment, he observed that the disruption of blood supply to the liver tissue resulted in a size...
14.4K
02:40The Eukaryotic Promoter Region
18.8K
The eukaryotic promoter region is a segment of DNA located upstream of a gene. It contains an RNA polymerase binding site, a transcription start site, and several cis-regulatory sequences. The proximal promoter region is located in the vicinity of the gene and has cis-regulatory sequences and the core promoter. The core promoter is the binding site for RNA polymerase and is usually located between -35 and +35 nucleotides from the transcription start site. The distal promoter regions are...
18.8K
02:40The Eukaryotic Promoter Region
3.9K
3.9K
01:23Factors Affecting Protein-Drug Binding: Drug Interactions
597
Drug interactions are a critical aspect of pharmacology and can occur when two or more drugs compete for the same binding site. This competition can result in one drug displacing another, altering the effect of the displaced drug. Drug interactions are complex processes that rely heavily on how much of the displacer drug is present and how strongly it can bind to the same sites as the displaced drug.
Displacement interactions can have varying outcomes, ranging from toxicity to virtually...
Displacement interactions can have varying outcomes, ranging from toxicity to virtually...
597
00:50Anaphase Promoting Complex
3.4K
The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...
3.4K
02:04Protein-protein Interfaces
14.7K
Many proteins form complexes to carry out their functions, making protein-protein interactions (PPIs) essential for an organism's survival. Most PPIs are stabilized by numerous weak noncovalent chemical forces. The physical shape of the interfaces determines the way two proteins interact. Many globular proteins have closely-matching shapes on their surfaces, which form a large number of weak bonds. Additionally, many PPIs occur between two helices or between a surface cleft and a...
14.7K