title: The N-terminal 11 amino acids of human erythrocyte band 3 are critical for aldolase binding and protein phosphorylation: implications for band 3 function.
abstract: The 911 amino acid band 3 (SLC4A1) is the major intrinsic membrane protein of red cells and is the principal Cl-/HCO3- exchanger. The N-terminal cytoplasmic domain of band 3 anchors the spectrin-based membrane skeleton to the lipid bilayer through its interaction with ankyrin and also binds glycolytic enzymes and hemoglobin. We identified a son of a consanguineous marriage with severe anemia in association with marked deficiency of band 3 (12% +/- 4% of normal). Direct nucleotide sequencing of SLC4A1 gene demonstrated a single base substitution (T --> C) at position + 2 in the donor splice site of intron 2, resulting in the generation of a novel mutant protein. Biochemical characterization of the mutant protein showed that it lacked the first 11 N-terminal amino acids (band 3 Neapolis). The expression of the mutant protein resulted in the complete absence of membrane-bound aldolase, and the mutant band 3 could not be tyrosine phosphorylated. The ability of the malarial parasite P falciparum to invade these red cells was significantly decreased. The identification of a novel band 3 mutant and its structural and functional characterization enabled us to identify pivotal roles for the 11 N-terminal amino acids in several protein functions and, in turn, in red-cell physiology.
authors.affiliation: Department of Pediatrics, Second University of Naples, Italy. silverio.perrotta@unina2.it
authors.forename: Silverio
authors.initials: S
authors.lastname: Perrotta
authors.forename: Adriana
authors.initials: A
authors.lastname: Borriello
authors.forename: Andrea
authors.initials: A
authors.lastname: Scaloni
authors.forename: Lucia
authors.initials: L
authors.lastname: De Franceschi
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Brunati
authors.forename: Francesco
authors.initials: F
authors.lastname: Turrini
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Nigro
authors.forename: Emanuele Miraglia
authors.initials: EM
authors.lastname: del Giudice
authors.forename: Bruno
authors.initials: B
authors.lastname: Nobili
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Conte
authors.forename: Francesca
authors.initials: F
authors.lastname: Rossi
authors.forename: Achille
authors.initials: A
authors.lastname: Iolascon
authors.forename: Arianna
authors.initials: A
authors.lastname: Donella-Deana
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Zappia
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Poggi
authors.forename: William
authors.initials: W
authors.lastname: Anong
authors.forename: Philip
authors.initials: P
authors.lastname: Low
authors.forename: Narla
authors.initials: N
authors.lastname: Mohandas
authors.forename: Fulvio
authors.initials: F
authors.lastname: Della Ragione
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001457:Anion Exchange Protein 1, Erythrocyte / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D004910:Erythrocyte Membrane / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004912:Erythrocytes / Q000737:chemistry / Q000378:metabolism; D005634:Fructose-Bisphosphate Aldolase / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D006720:Homozygote; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation; D010963:Plasmodium falciparum / Q000502:physiology; D011485:Protein Binding; D012326:RNA Splicing / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D001457:Anion Exchange Protein 1, Erythrocyte; D012333:RNA, Messenger; D005634:Fructose-Bisphosphate Aldolase; D005947:Glucose