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Molecular and functional changes associated with APE1/Ref‐1 loss of expression reveal its multifunctional nature in mammalian cells
Author(s) -
Tell Gianluca,
Vascotto Carlo,
Cesaratto Laura,
Deganuto Marta,
Romanello Milena,
Quadrifoglio Franco
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.2_supplement.289
Subject(s) - microbiology and biotechnology , biology , dna damage , dna repair , cytoskeleton , base excision repair , intracellular , mitochondrion , regulator , mutant , proteomics , gene , cell , dna , genetics
APE1/Ref‐1 protects cells from oxidative stress by acting as a transcriptional regulator of antioxidant genes and as a central enzyme in base excision repair pathways of DNA lesions. While it is known that loss of Ape1 expression is associated with significant biological effects, the molecular mechanism(s) involved are still poorly understood. Here, we combined mRNA expression profiling and proteomics to determine the molecular changes associated with Ape1 loss‐of‐expression induced by siRNA technology. This approach identified a role of Ape1 in apoptosis, cell growth, control of intracellular redox state, mitochondrial function and cytoskeletal structure. To dissect direct and indirect effects we performed knock‐in experiments using wild type and various Ape1 mutants as well. Two of these latter (i.e. C65S and C310S) were able to rescue mitochondrial depolarisation and cytoskeleton perturbation but not cell cycle arrest and apoptosis. This indicates that the wild‐type Ape1 protein has structural components that function in several distinct central cellular roles and strongly support the notion that, besides its DNA‐repair activity, additional functions of Ape1 are important for cell viability. Our data reveal molecular determinants of the multifunctional nature of Ape1 protein.