Spherocytosis-Related L1340P Mutation in Ankyrin Affects Its Interactions with Spectrin

Abstract

Previously, we reported a new missense mutation in the ANK1 gene that correlated with the hereditary spherocytosis phenotype. This mutation, resulting in L1340P substitution (HGMD CM149731), likely leads to the changes in the conformation of the ankyrin ZZUD domain important for ankyrin binding to spectrin. Here, we report the molecular and physiological effects of this mutation. First, we assessed the binding activity of human β-spectrin to the mutated ZZUDL1340P domain of ankyrin using two different experimental approaches—the study of association and dissociation responses of the spectrin–ankyrin binding domain and a sedimentation assay. In addition, we documented the changes in morphology caused by the overexpressed ankyrin ZZUD domain in human cell models. Our results prove the key role of the L1340 aa residue for the correct alignment of the ZZUD domain of ankyrin, which results in binding the latter with spectrin within the erythrocyte membrane. Replacing L1340 with a proline residue disrupts the spectrin-binding activity of ankyrin.

Novel Variant of the SLC4A1 Gene Associated with Hereditary Spherocytosis

“…In our previous study, we reported new variants in the genes correlated with the hereditary hemolytic anemia phenotype including HS in a few Polish families [ 37 , 38 , 39 , 40 , 41 ]. In this report, we presented a Polish family with a novel missense mutation in the SLC4A1 gene.…”

“…Used predefined data based on information deposited in biological databases and in the literature may not take into account undescribed and unverified facts for specific variants in genes that have not yet been linked to clinical symptoms or molecular mechanisms. It should also be mentioned that experimental verification of the functional effect of the observed mutation is not always relatively easy to perform, as our team did in the case of the ankyrin variant (p.L1340P) [ 37 ].…”