JAB1

GWB-8ECC77

Synthetic peptide: SEYQTIPLNKIEDFGV conjugated to KLH corresponding to amino acids 201-216 of Human JAB1. The corresponding sequence is identical in mouse and rat.

Whole extract of human A431 cells mouse NIH-3T3 cells (Western blot). Rat PC12 cells (immunoprecipitation). Human breast carcinoma (indirect immunoperoxidase staining).

Cytoplasmic and Nuclear

Whole antiserum is fractionated and then further purified by ion-exchange chromatography to provide the IgG fraction of antiserum that is essentially free of other rabbit serum proteins. Storage

IHC-P: Use at a dilution of 1/100 this is recommended using formalin-fixed paraffin-embedded sections of human breast carcinoma. IP: Use at an assay dependent dilution. 20-40 µ g of the antibody immunoprecipitates J from 0. 45 mg of RIPA extracts of rat PC12 cells. WB: Use at a dilution of 1/500 this is recommended using a whole extract of human A431 cells and mouse NIH-3T3 cells and a chemiluminescent detection reagent. Predicted

Cytoplasmic and Nuclear Jun activation domain-binding protein 1 (JAB1) also designated COP9 subunit 5 (COPS5) or SGN5 is a coactivator of AP1 transcription factor that also promotes degradation of the cyclin-dependent kinase inhibitor p27Kip1. JAB1 interacts with c-Jun AP1 containing complexes and enhances transactivation from AP1 dependent promoters. It also interacts with Jun D but not with Jun B or v-Jun. JAB1 is highly conserved in evolution and is widely expressed in mammalian tissues. It is localized both the nucleus and the cytoplasm. It interacts with the cytoplasmic domain of the alphaL/beta2 integrin LFA1. Following LFA1 engagement the nuclear pool of JAB1 increases and activation of an AP1 driven promoter is enhanced. Interaction of JAB1 with the nuclear progesterone receptor and the steroid receptor activator (SRC1) was reported. JAB1 is a stability and activity regulator of Hypoxia - inducible factor 1 (HIF1) a transcription factor that controls activation of several genes responsive to the cellular oxygen tension. The macrophage migration inhibitory factor (MIF) associates with JAB1 in the cytosol near the plasma membrane. Endogenous MIF inhibits JAB1-induced AP1 transcriptional activity. JAB1 is a subunit of the COP9 regulatory complex. COP9 cleaves the ubiquitin-like protein Nedd8 from the Cul1 subunit of SCF ubiquitin ligases. A metalloprotease motif in JAB1 plays a role in this isopeptidase activity. Breakdown of the cyclin dependent kinase inhibitor p27Kip1 is promoted by JAB1. The latter expression in several cancers inversely correlates with p27Kip1 and may reflect tumor aggressiveness. A possible involvement of JAB1 in atherosclerosis was also reported. Involvement of JAB1 in degradation of the suppressors p53 and smad4 was described recently.

Component of the CSN complex composed of COPS1/GPS1 COPS2 COPS3 COPS4 COPS5 COP6 COPS7 (COPS7A or COPS7B) and COPS8. In the complex it probably interacts directly with COPS1 COPS2 COPS4 COPS6 and COPS7 (COPS7A or COPS7B). Also exists as monomeric form. Interacts with TP53 MIF JUN UCHL1 NCOA1 HIF1A CDKN1B BCL3 GFER PGR LHCGR SMAD4 SMAD7 ID1 ID3 ITGB2 and TOP2A. Part of a complex consisting of RANBP9 Ran DYRK1B and COPS5.

The JAMM motif is essential for the protease activity of the CSN complex resulting in deneddylation of cullins. It may constitute the catalytic center of the complex (By similarity).

Contains 1 MPN (JAB/Mov34) domain.