| Modification Notes |
APOBEC (apolipoprotein B mRNA editing enzyme, catalytic) proteins inhibit retroviruses by deaminating cytosine residues of viral RNA and DNA. APOBEC4 (apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 4), also known as C1orf169, is a 367 amino acid protein that belongs to the AID/APOBEC family of polynucleotide deoxycytidine deaminases whose primary function is to catalyze the conversion of cytidine to uridine. Expressed predominately in testis, APOBEC4 uses zinc as a cofactor to convert cytidine to uridine, an event that is important for RNA editing. The gene encoding APOBEC4 maps to human chromosome 1, which spans 260 million base pairs, contains over 3,000 genes and comprises nearly 8% of the human genome. Chromosome 1 houses a large number of disease-associated genes, including those that are involved in familial adenomatous polyposis, Stickler syndrome, Parkinsons Disease, Gaucher disease, schizophrenia and Usher syndrome. Aberrations in chromosome 1 are found in a variety of cancers, including head and neck cancer, malignant melanoma and multiple myeloma. |