- Regulation of the cell-cycle-dependent internal ribosome entry site of the PITSLRE protein kinase: roles of Unr (upstream of N-ras) protein and phosphorylated translation initiation factor eIF-2alpha. Tinton, S.A., Schepens, B., Bruynooghe, Y., Beyaert, R., Cornelis, S. Biochem. J. (2005)