C1q And Tumor Necrosis Factor Related Protein 1 (C1QTNF1)

The deduced protein contains 379 amino acids. The extracellular N terminus contains a TNF family cysteine-rich region, followed by a transmembrane domain, a C-terminal collagen-like sequence of 14 Gly-X-Y repeats, and a globular domain. Northern blot analysis detected prominent expression in heart and lower expression in placenta, liver, skeletal muscle, kidney, prostate and ovary. Little to no expression was detected in other tissues examined.

In transfected HEK293 and COS cells, epitope-tagged GIP was expressed in vesicular structures surrounding the nucleus and near the cell surface. Western blot analysis detected epitope-tagged GIP at about 40 kD and 130 kD, suggesting GIP can form trimers