HBV XAg Transactivated Protein 5 (XTP5)

HA-8, that differed in an HLA-identical sib donor-derived B-cell line. Mass spectrometric and CTL analyses defined a nonapeptide, RTLDKVLEV, as the epitope recognized by the CTL line. Variants of the nonapeptide were less well presented to the CTL line, partly due to poor transportation by TAP1. HA-8 recognition differences may result from altered antigenic processing rather than differences in interaction with major histocompatibility complex molecules or the T-cell receptor.

The predicted 647-amino acid KIAA0020 protein has a tyrosine phosphorylation site and a prokaryotic membrane lipoprotein lipid attachment site. Northern blot analysis detected ubiquitous expression, with highest levels in lung, liver, kidney, testis, ovary, and colon.