pfam05020: zf-NPL4 (This model is not part of the current CDD release)
NPL4 family, putative zinc binding region
The HRD4 gene was identical to NPL4, a gene previously implicated in nuclear transport. Using a diverse set of substrates and direct ubiquitination assays, analysis revealed that HRD4/NPL4 is required for a poorly characterised step in ER-associated degradation after ubiquitination of target proteins but before their recognition by the 26S proteasome. This region of the protein contains possibly two zinc binding motifs. Npl4p physically associates with Cdc48p via Ufd1p to form a Cdc48p-Ufd1p-Npl4p complex. The Cdc48-Ufd1-Npl4 complex functions in the recognition of several polyubiquitin-tagged proteins and facilitates their presentation to the 26S proteasome for processive degradation or even more specific processing.