Pcna Protein (Proliferating Cell Nuclear Antigen) plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.
Protein Name: Proliferating Cell Nuclear Antigen
Gene: PCNA
UniProt ID: P12004
PDB Structure ID: 1AXC
Molecular Weight: 28.8 kDa
Subcellular Localization: Nucleus
Protein Family: PCNA family, DNA clamp proteins
PCNA (Proliferating Cell Nuclear Antigen) is a homotrimeric ring-shaped protein that functions as a sliding clamp for DNA polymerases during DNA replication and repair. Often called the "molecular toolbelt" of the cell, PCNA serves as a central platform for recruiting proteins involved in DNA metabolism.
PCNA forms a ring-shaped homotrimer:
- Each monomer contains two topologically closed domains
- The central channel encircles DNA
- Interdomain connecting loop (IDCL) mediates protein-protein interactions
During S-phase, PCNA:
- Tethers DNA polymerases δ and ε to the template
- Increases processivity of polymerases 1000-fold
- Coordinates leading and lagging strand synthesis
PCNA is essential for multiple DNA repair pathways:
- Nucleotide Excision Repair (NER): Recruits repair proteins to damaged sites
- Base Excision Repair (BER): Coordinates gap-filling synthesis
- Mismatch Repair (MMR): Directs excision and resynthesis
PCNA is regulated by:
- Monoubiquitination: Initiates translesion synthesis
- K63-linked polyubiquitination: Promotes error-free repair
- Phosphorylation: Regulates protein interactions
In AD brains:
- PCNA expression is altered in neurons
- DNA repair capacity declines with age
- Accumulation of DNA damage contributes to neurodegeneration
- Impaired DNA repair mechanisms in dopaminergic neurons
- PCNA involvement in mitochondrial DNA maintenance
- Connection to PINK1/Parkin mitophagy pathway
- [[mechanisms/dna-damage-repair]] - DNA Damage Repair Pathway
- [[genes/ube2v2]] - UBE2V2, involved in PCNA ubiquitination
- [[genes/ube2n]] - UBE2N, partners with UBE2V2 for PCNA polyubiquitination
Pcna Protein (Proliferating Cell Nuclear Antigen) plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.
The study of Pcna Protein (Proliferating Cell Nuclear Antigen) has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
- Mailand N et al. "Regulation of PCNA polyubiquitination in human cells." J Cell Biol. 2013;202(2):231-240.
- Boehm EM et al. "The roles of PCNA in DNA damage repair and replicative stress responses." DNA Repair (Amst). 2015;32:33-39.