pyrin & HIN domain-containing protein 1 (interferon-inducible protein X, PYHIN1, IFIX)

Function

• major mediator of the tumor suppressor activity of IFN in breast cancer cells
• promotes ubiquitination & subsequent degradation of MDM2, which leads to p53/TP53 stabilization
• promotes ubiquitination & subsequent degradation of HDAC1, which in turn enhances maspin expression, & impairs invasive activity of cancer cells
• interacts with MDM2

Structure

• HIN-200 domain mediates interaction with MDM2 belongs to the HIN-200 family
• contains 1 DAPIN domain
• contains 1 HIN-200 domain

Compartment

• isoform 1: nucleus, nucleoplasm
• isoform 3: nucleus, nucleoplasm
• isoform 5: nucleus, in speckles

Alternative splicing

named isoforms=6

Expression

• expressed in spleen, lymph node & peripheral blood leukocytes, & at lower levels in thymus, bone marrow & fetal liver
• induced by IFNalpha & IFNgamma in hematopoietic cancer cells

Pathology

• down-regulated in breast tumors

More general terms

• uncharacterized protein

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:1496
• UniProt: http://www.uniprot.org/uniprot/Q6K0P9.html