Inactive cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAHP)

Sialic acids are components of carbohydrate chains of glycoconjugates and are involved in cell-cell recognition and cell-pathogen interactions. That protein has no CMP-N- acetylneuraminate monooxygenase activity and isn't able to convert CMP-N-acetylneuraminic acid (CMP-Neu5Ac) to its hydroxylated derivative CMP-N-glycolylneuraminic acid (CMP- Neu5Gc), a sialic acid abundantly expressed at the surface of many cells in vertebrates (PubMed:9624188).

However, it may play a role in Wnt signaling (PubMed:19890979). .