Tumor Protein D53 (TPD53)

TPD53 contains a coiled-coil domain and may form homo- or hetero-dimer with TPD52 family members. The protein is reported to be involved in cell proliferation and calcium signaling. It also interacts with the mitogen-activated protein kinase kinase kinase 5 (MAP3K5/ASK1) and positively regulates MAP3K5-induced apoptosis. Multiple alternatively spliced transcript variants have been observed, but the full-length nature of some variants has not yet been determined. Northern blot analysis revealed that D53 is expressed as a 1.5-kb transcript in human kidney, skin, and some breast tumors. Northern blotting also showed that D52 and D53 transcription in breast carcinoma cells is dependent upon estradiol. In vitro differentiation of K-562 leukemia cells by TPA caused D53 expression to decrease.