Ankyrin Repeat Family A2 (ANKRA2)

ANKRA2 has 3 consecutive ankyrin repeats, 2 regions with low homology to ankyrin repeats, and multiple potential phosphorylation sites. Northern blot analysis revealed expression of a major 2.0-kb transcript in all tissues tested, a 2.7-kb transcript in brain, spleen, lung, liver, and kidney, and a 2.5-kb transcript in testis. Library screening and EST database searching confirmed thatANKRA2 splice variants exist. GST pull-down, mutation, and immunoprecipitation analyses showed that the ankyrin repeats and the last 22 C-terminal residues of ANKRA2 interact with the N-terminal proline-rich 19 residues of the megalin tail, but not with LRP1. ANKRA2 expression is enriched in apical membranes of the proximal tubule.