Integrin Alpha FG GAP Repeat Containing Protein 1 (ITFG1)

Using bioinformatics and high-throughput cell-based screening assays to identify novel T-cell factors, Fiscella et al. (2003) cloned ITFG1, which they called TIP. The predicted 612-amino acid protein has an N-terminal signal peptide, a C-terminal transmembrane domain, and 12 potential N-glycosylation sites. It shares 89% amino acid identity with mouse Tip. Northern blot analysis revealed ubiquitous expression of TIP in human tissues and cell lines. Western blot analysis showed that TIP was glycosylated.Fiscella et al. (2003) found that mouse and human T cells exposed to TIP secreted IFNG, TNF, and IL10. TIP did not induce IL2 secretion or T-cell proliferation. TIP induced phosphorylation of p44 MAPK (MAPK3) and p42 MAPK (MAPK1). In vivo, TIP had a protective effect in a mouse model of acute graft-versus-host disease.