RanBP-type and C3HC4-type zinc finger-containing protein 1/SHARPIN (IPR026261)

Short name: RBCK1/SHARPIN

Overlapping homologous superfamilies


Family relationships



This entry consists of RanBP-type and C3HC4-type zinc finger-containing protein 1 (RBCK1, also known as HOIL-1) and SHARPIN. Both are components of the E3 ligase complex LUBAC (linear ubiquitin chain assembly complex). LUBAC is composed of HOIP, RBCK1/HOIL-1, and SHARPIN. HOIP is the catalytic subunit and its E3 activity can be effectively activated by HOIL-1 or SHARPIN [PMID: 28978479]. The LUBAC complex catalyses the formation of linear ubiquitin chains and regulates immune and apoptopic signaling pathways [PMID: 21455173, PMID: 21455180, PMID: 21455181].

RBCK1/HOIL-1 contains an ubiquitin-like (UBL) domain followed by a Npl4 zinc finger (NZF) domain and a RBR (RING-between-RING) domain in the C-terminal portion of the protein. RBCK1 is a RING-between-RING E3 ligase, and it has also been shown to act as a transcriptional activator [PMID: 20103625]. SHARPIN also contains a UBL domain and a Ub-binding NZF domain, but lacks the RBR domain and has a additional N-terminal pleckstrin homology (PH) domain [PMID: 21455181, PMID: 22549881].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.