Cytosolic 10-formyltetrahydrofolate dehydrogenase

ALDH1L1 (cytosolic 10-formyltetrahydrofolate dehydrogenase) is an NADP(+)-dependent enzyme that catalyzes the conversion of 10-formyltetrahydrofolate to tetrahydrofolate and carbon dioxide, functioning in one-carbon metabolism (UniProt: O75891). The protein may also possess aldehyde dehydrogenase activity toward formaldehyde and other aldehydes. It is expressed as a 902-amino-acid cytosolic protein in humans.

ALDH1L1 participates in folate-dependent metabolic pathways critical for nucleotide synthesis and methylation reactions. No baseline disease associations are documented in UniProt for this protein.

ALDH1L1 is upregulated in Alzheimer's disease brain tissue. Post-mortem analysis of AD brain versus age-matched controls using TMT-labeled quantitative proteomics across four subcellular fractions (P2, P3, S2, S3) showed a mean log2 fold-change of +0.96, indicating elevated protein abundance in the disease state (Chaparral AD proteomics). This upregulation may reflect altered one-carbon metabolism or detoxification responses associated with AD neuropathology.