A novel ENU-generated truncation mutation lacking the spectrin-binding and C-terminal regulatory domains of Ank1 models severe hemolytic hereditary spherocytosis

作者：Hughes Michael R; Anderson Nicole; Maltby Steven; Wong Justin; Berberovic Zorana; Birkenmeier Connie S; Haddon D James; Garcha Kamal; Flenniken Ann; O**orne Lucy R; Adamson S Lee; Rossant Janet; Peters Luanne L; Minden Mark D; Paulson Robert F; Wang Chen; Barber Dwayne L; McNagny Kelly M; Stanford William L^*

来源：Experimental Hematology, 2011, 39(3): 305-320.

DOI：10.1016/j.exphem.2010.12.009

Objective. Hereditary spherocytosis (HS) is a heterogeneous group of spontaneously arising and inherited red blood cell disorders ranging from very mild subclinical cases to severe and life-threatening cases, with symptoms linked directly to the severity of the mutation at the molecular level. We investigated a novel mouse model in which the heterozygotes present with the diagnostic hallmarks of mild HS and surviving homozygotes phenocopy severe hemolytic HS.
Materials and Methods. We used N-ethyl-N-nitrosourea mutagenesis to generate random point mutations in the mouse genome and a dominant screen to identify mouse models of human hematopoietic disease. Gene mapping of the HS strain revealed a unique in-frame nonsense mutation arising from a single base transversion in exon 27 of Ank1 (strain designation: Ank1(E924X)). Employing conventional hematopoietic, pathological, biochemical, and cell biology assays, we characterized heterozygous and homozygous Ank1(E924X) mice at the biochemical, cellular, and pathophysiological levels.
Results. Although Ank1(E924X/E924X): red blood cell ghosts lack abundant full-length ankyrin-1 isoforms, N-terminal epitope ankyrin-1 antibodies reveal a band consistent with the theoretical size of a truncated mutant ankyrin-1. Using domain-specific antibodies, we further show that this protein lacks both a spectrin-binding domain and a C-terminal regulatory domain. Finally, using antisera that detect C-terminal residues of the products of alternative Ank1 transcripts, we find unique immunoreactive bands not observed in red blood cell ghosts from wild-type or Ank1(E924X) heterozygous mice, including a band similar in size to full-length ankyrin-1.
Conclusions. The Ank1(E924X) strain provides a novel tool to study Ank1 and model HS.

• 出版日期2011-3
• 单位河北医科大学