LEO1, Paf1/RNA Polymerase II Complex Component, Homolog (LEO1)

LEO1, parafibromin (CDC73), CTR9, and PAF1 form the PAF protein complex that associates with the RNA polymerase II subunit POLR2A and with a histone methyltransferase complex. The deduced 666-amino acid protein has an N-terminal AAA domain and a C-terminal domain that shares a high degree of similarity with yeast Leo1. LEO1 has several putative phosphorylation sites and several putative nuclear localization signals in the C terminus. The AAA domain was found in mouse, rat, and human LEO1 proteins but not in yeast, nematode, or fly Leo1 homologs. Northern blot analysis detected a 2.4-kb transcript highly expressed in skeletal muscle and heart, and more weakly expressed in placenta, liver, and other tissues. Fluorescence-tagged LEO1 localized predominantly in the nucleus of transfected human fibroblasts.