C/EBP Homology Protein (CHOP), also known as Growth Arrest and DNA Damage Inducible Protein 153 (GADD153), DNA–damage-inducible transcript 3 (DDIT3) and C/EBPz, is a transcription factor that mediates one of the three arms of unfolded protein response (UPR) adaptation to endoplasmic reticulum (ER) stressors. It is a 29 kDa protein that serves as a dominant negative inhibitor of C/EBPs. CHOP is composed of an amino-terminal transcription activation domain and a carboxy-terminal basic amino-acid-rich DNA-binding domain and a leucine zipper dimerization domain. It is present at low levels in the cytosol under non-stressed conditions. During ER stress, the ER stress-activated kinase PERK phosphorylates eIF2α causing a decrease in its activity that increases the translation of ATF4 mRNA. ATF4 binds to and activates the CHOP promoter thereby increasing its levels during ER stress. CHOP is involved in the response of many diseases (ischemia, neurodegeneration, cancer, diabetes) which makes this an attractive marker for many therapeutic areas.


CHOP Singleplex Products

Our CHOP immunoassays provide fast, accurate, reproducible, and highly sensitive measurements of CHOP. MSD’s MULTI-ARRAY technology uses simple protocols, requires minimal sample, and quantifies analyte concentration over a wide dynamic range.


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