Family With Sequence Similarity 76, Member B (FAM76B)

FAM76B, Belongs to the FAM76 family. FAM76A and FAM76B pair of paralogues. A sequence alignment of these two proteins highlighted their high degree of conservation, except in the region containing the His-repeat. As hypothesized, the paralogue without the His-tract, FAM76A, presented a diffuse nucleoplasmic staining, while the protein with the polyHis segment, FAM76B, accumulated in nuclear speckles. Similar results were obtained for other pairs of paralogous proteins such as DYRK1A/DYRK1B or POU4F2/POU4F3. Thus, these findings further indicate that the His-repeats in these proteins are necessary for their localization to nuclear speckles.