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Band 3 Chur: a variant associated with band 3‐deficient hereditary spherocytosis and substitution in a highly conserved position of transmembrane segment 11
Author(s) -
Maillet Philippe,
Vallier Agnès,
Reinhart Walter H.,
Wyss Erwin J.,
Ott Peter,
Texier Pascale,
Baklouti Faouzi,
Tanner Michael J. A.,
Delaunay Jean,
Alloisio Nicole
Publication year - 1995
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1995.tb05393.x
Subject(s) - hereditary spherocytosis , band 3 , amino acid , transmembrane protein , genetics , transmembrane domain , biology , exon , mutation , point mutation , microbiology and biotechnology , gene , membrane protein , receptor , membrane
Summary. We studied a large Swiss family with dominantly inherited hereditary spherocytosis and band 3 (anion exchanger 1, AE1) deficiency. Band 3 cDNA was analysed by single‐strand conformation polymorphism analysis and nucleotide sequencing. A new point mutation was found: G771D (GGC→GAC). This change was present in all eight investigated patients but absent in four healthy members of the family. It is located at a highly conserved position in the middle of transmembrane segment 11, introducing a negative charge in a stretch of 16 apolar or neutral residues. None of the six amino‐acid substitutions already known in this region as being associated with band 3 deficiency were recorded. To rule out any major transcriptional or post‐transcriptional defect, we evaluated the amount of band 3 mRNA by RNase mapping using a band 3‐protein 4.1 chimaeric probe. Similar mRNA amounts were present in patients and controls. Our results strengthen the view that some amino‐acids, that are well conserved throughout the AE family, may be crucial for the insertion and/or the stabilization of band 3 within the lipid bilayer. At the present time, most of the mutations altering such residues are located in the C‐terminal region of band 3.