NBR1
NBR1 (NBR1 autophagy cargo receptor, also known as Next to BRCA1 gene 1 protein, CA125, KIAA0049, 1A1-3B and M17S2) is a ubiquitin-binding autophagy adapter. It delivers ubiquitinated proteins to autophagosomes and contributes to host defence and intracellular homeostasis. Browse Assay Genie's current range of NBR1 research reagents below, or read on for the biology behind the target.
NBR1 is a ubiquitin-binding autophagy adapter with a double function in selective autophagy. It acts as a shuttle that brings ubiquitinated proteins to autophagosomes, and it also takes part in the formation of protein aggregates. According to the NCBI Gene summary, it works as a specific autophagy receptor for the selective degradation of peroxisomes, forming intracellular inclusions with ubiquitylated autophagic substrates.
The NBR1 protein has roles beyond cargo delivery. It helps regulate the innate immune response by modulating type I interferon production and by targeting ubiquitinated IRF3 for autophagic degradation. In response to oxidative stress, it raises SQSTM1 levels, phosphorylation and body formation by preventing the autophagic degradation of SQSTM1. This in turn activates the KEAP1-NRF2/NFE2L2 antioxidant pathway. NBR1 also has a non-autophagy role, mediating the shuttle of IL-12 to late endosomes for subsequent secretion. UniProt lists its locations as the cytoplasm, autophagosomes, lysosomes and the M line of the sarcomere in myofibrils.
The NBR1 gene lies on chromosome 17q21.1, close to the BRCA1 tumour suppressor gene, which gave rise to the name neighbour of BRCA1 gene 1. The protein was first identified as an ovarian tumour antigen monitored in ovarian cancer, hence the earlier names CA125 and membrane component, chromosome 17, surface marker 2. It contains a B-box/coiled-coil motif, found in many genes with transformation potential, and HGNC places it in the ZZ-type zinc finger group. Alternative splicing produces multiple transcript variants. Mouse and rat both have an Nbr1 ortholog.
NBR1 shuttles ubiquitinated proteins to autophagosomes and helps form protein aggregates, making it a key receptor for studying selective autophagy.
NBR1 modulates type I interferon production and targets ubiquitinated IRF3 for autophagic degradation, linking autophagy to host defence.
By preventing autophagic degradation of SQSTM1, NBR1 activates the KEAP1-NRF2/NFE2L2 antioxidant pathway in response to oxidative stress.
NBR1 acts as a receptor for selective peroxisome degradation and was first identified as an ovarian tumour antigen.
NBR1 is a ubiquitin-binding autophagy adapter. It carries ubiquitinated proteins to autophagosomes, helps form protein aggregates and acts as a receptor for peroxisome degradation. It also modulates type I interferon production and the KEAP1-NRF2/NFE2L2 antioxidant pathway, and shuttles IL-12 to late endosomes.
NBR1 was originally identified as an ovarian tumour antigen, which explains the names CA125 and membrane component, chromosome 17, surface marker 2 (M17S2). The name neighbour of BRCA1 gene 1 reflects its location next to BRCA1 on chromosome 17. KIAA0049 and 1A1-3B are other aliases.
Yes. Mouse and rat each have an ortholog named Nbr1, so the gene can be studied in common rodent models. Alternative splicing of the human gene gives multiple transcript variants. Check the datasheet of any product for its validated reactivity.
Autophagy adapters, antioxidant pathway components, innate immune regulators and neighbouring tumour suppressor targets related to NBR1.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q14596; product specifications from Assay Genie datasheets.