APEX2

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Description

The APEX2 (apurinic/apyrimidinic endodeoxyribonuclease 2) is a protein-coding gene located on chromosome X.

APEX2 functions as a weak apurinic/apyrimidinic (AP) endodeoxyribonuclease in the DNA base excision repair (BER) pathway, repairing DNA lesions induced by oxidative and alkylating agents. It initiates repair by cleaving the phosphodiester backbone near the damage, creating a single-strand break with specific ends. APEX2 also displays 3'-5' exonuclease and 3'-phosphodiesterase activities, removing mismatched nucleotides and damaged termini in DNA. It participates in the PCNA-dependent BER pathway in the nucleus and plays a role in reversing blocked 3' DNA ends. APEX2 is essential for somatic hypermutation and class switch recombination of immunoglobulin genes, as well as proper cell cycle progression in lymphocytes. Its interaction with PCNA is triggered by reactive oxygen species and is enhanced by uracil misincorporation.

APEX2 is also known as APE2, APEXL2, XTH2, ZGRF2.

Associated Diseases

• cancer
• ringed hair disease
• Griscelli syndrome type 3
• uncombable hair syndrome
• microcephaly-albinism-digital anomalies syndrome
• pili bifurcati
• oculocutaneous albinism type 3
• reticular dysgenesis
• alopecia, androgenetic, 1
• wooly hair, autosomal recessive 3
• combined immunodeficiency with skin granulomas
• X-linked sideroblastic anemia 1
• Cernunnos-XLF deficiency
• hemoglobin D disease
• primary familial polycythemia due to EPO receptor mutation
• dehydrated hereditary stomatocytosis