Zinc finger protein 91 homolog is a protein that in humans is encoded by the ZFP91 gene.

The protein encoded by this gene is a member of the zinc finger family of proteins. The gene product contains C2H2-type domains, which are the classical zinc finger domains found in numerous nucleic acid-binding proteins. This protein functions as a regulator of the non-canonical NF-kappaB pathway in lymphotoxin-beta receptor signaling. Alternative splicing results in multiple transcript variants. A read-through transcript variant composed of ZFP91 and the downstream CNTF gene sequence has been identified, but it is thought to be non-coding. Read-through transcription of ZFP91 and CNTF has also been observed in mouse. A ZFP91-related pseudogene has also been identified on chromosome 2. [provided by RefSeq, Oct 2010].
Function: Atypical E3 ubiquitin-protein ligase that mediates 'Lys-63'-linked ubiquitination of MAP3K14/NIK, leading to stabilize and activate MAP3K14/NIK. It thereby acts as an activator of the non-canonical NF-kappa-B2/NFKB2 pathway. May also play an important role in cell proliferation and/or anti-apoptosis.