| Structural highlights
Disease
B3AT_HUMAN Defects in SLC4A1 are the cause of elliptocytosis type 4 (EL4) [MIM:109270. EL4 is a Rhesus-unlinked form of hereditary elliptocytosis, a genetically heterogeneous, autosomal dominant hematologic disorder. It is characterized by variable hemolytic anemia and elliptical or oval red cell shape.[1] [2] Defects in SLC4A1 are the cause of spherocytosis type 4 (SPH4) [MIM:612653; also known as hereditary spherocytosis type 4 (HS4). Spherocytosis is a hematologic disorder leading to chronic hemolytic anemia and characterized by numerous abnormally shaped erythrocytes which are generally spheroidal.[3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] Defects in SLC4A1 are the cause of renal tubular acidosis, distal, autosomal dominant (AD-dRTA) [MIM:179800. A disease characterized by reduced ability to acidify urine, variable hyperchloremic hypokalemic metabolic acidosis, nephrocalcinosis, and nephrolithiasis. Defects in SLC4A1 are the cause of renal tubular acidosis, distal, with hemolytic anemia (dRTA-HA) [MIM:611590. A disease characterized by the association of hemolytic anemia with distal renal tubular acidosis, the reduced ability to acidify urine resulting in variable hyperchloremic hypokalemic metabolic acidosis, nephrocalcinosis, and nephrolithiasis. Defects in SLC4A1 are the cause of renal tubular acidosis, distal, with normal red cell morphology (dRTA-NRC) [MIM:611590. A disease characterized by reduced ability to acidify urine, variable hyperchloremic hypokalemic metabolic acidosis, nephrocalcinosis, and nephrolithiasis.
Function
B3AT_HUMAN Band 3 is the major integral glycoprotein of the erythrocyte membrane. Band 3 has two functional domains. Its integral domain mediates a 1:1 exchange of inorganic anions across the membrane, whereas its cytoplasmic domain provides binding sites for cytoskeletal proteins, glycolytic enzymes, and hemoglobin.
Publication Abstract from PubMed
Human erythrocyte band 3 inhibits glycolytic enzymes, including aldolase, by binding these cytoplasmic enzymes at its N-terminus. Phosphorylation of Y8 disrupts inhibition, and there is evidence that in vivo glycolysis levels in erythrocytes are regulated in part by a phosphorylation/dephosphorylation signaling pathway. The structural basis for control by phosphorylation has been investigated by NMR studies on a complex between aldolase and a synthetic peptide corresponding to the first 15 residues of band 3 (MEELQDDYEDMMEEN-NH2). The structure of this band 3 peptide (B3P) when it is bound to rabbit muscle aldolase was determined using the exchange-transferred nuclear Overhauser effect (ETNOE). Two hundred NMR structures for B3P were generated by simulated annealing molecular dynamics with NMR-derived distance restraints and excluding electrostatic terms. Twenty structures were further refined against a force field including full partial charges. The important conformational feature of B3P in the bound state is a folded loop structure involving residues 4-9 and M12 that surrounds Y8 and is stabilized by a hydrophobic cluster with the ring of Y8 sandwiched between the methyl groups of L4 and M12. Differential line broadening indicates that this loop structure binds aldolase in a relatively specific manner, while terminal regions are structurally heterogeneous. To better understand B3P inhibition of aldolase and the mechanism of phosphorylation control, a complex was modeled by docking B3P into the active site of aldolase and optimizing the fit using restrained molecular dynamics and energy minimization. The B3P loop is complementary in conformation to the beta-barrel central core containing the aldolase active site residues. Binding is electrostatic in nature with numerous ionic and hydrogen-bonding interactions involving several conserved lysine and arginine residues of aldolase. How phosphorylation of band 3 could disrupt inhibition was considered by modeling a phosphoryl moiety onto Y8 of B3P. An energetic analysis with respect to rigid phosphate rotation suggests that aldolase inhibition is reversed primarily because of electrostatic repulsion between B3P residues that destabilizes the B3P loop formed in the complex. This proposed intramolecular mechanism for blocking protein--protein association by electrostatic repulsion with the phosphoryl group may be applicable to other protein--protein signaling complexes.
Solution structure of a band 3 peptide inhibitor bound to aldolase: a proposed mechanism for regulating binding by tyrosine phosphorylation.,Schneider ML, Post CB Biochemistry. 1995 Dec 26;34(51):16574-84. PMID:8527430[18]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Jarolim P, Palek J, Amato D, Hassan K, Sapak P, Nurse GT, Rubin HL, Zhai S, Sahr KE, Liu SC. Deletion in erythrocyte band 3 gene in malaria-resistant Southeast Asian ovalocytosis. Proc Natl Acad Sci U S A. 1991 Dec 15;88(24):11022-6. PMID:1722314
- ↑ Schofield AE, Tanner MJ, Pinder JC, Clough B, Bayley PM, Nash GB, Dluzewski AR, Reardon DM, Cox TM, Wilson RJ, et al.. Basis of unique red cell membrane properties in hereditary ovalocytosis. J Mol Biol. 1992 Feb 20;223(4):949-58. PMID:1538405
- ↑ Maillet P, Vallier A, Reinhart WH, Wyss EJ, Ott P, Texier P, Baklouti F, Tanner MJ, Delaunay J, Alloisio N. Band 3 Chur: a variant associated with band 3-deficient hereditary spherocytosis and substitution in a highly conserved position of transmembrane segment 11. Br J Haematol. 1995 Dec;91(4):804-10. PMID:8547122
- ↑ Jarolim P, Palek J, Rubin HL, Prchal JT, Korsgren C, Cohen CM. Band 3 Tuscaloosa: Pro327----Arg327 substitution in the cytoplasmic domain of erythrocyte band 3 protein associated with spherocytic hemolytic anemia and partial deficiency of protein 4.2. Blood. 1992 Jul 15;80(2):523-9. PMID:1378323
- ↑ Jarolim P, Rubin HL, Brabec V, Chrobak L, Zolotarev AS, Alper SL, Brugnara C, Wichterle H, Palek J. Mutations of conserved arginines in the membrane domain of erythroid band 3 lead to a decrease in membrane-associated band 3 and to the phenotype of hereditary spherocytosis. Blood. 1995 Feb 1;85(3):634-40. PMID:7530501
- ↑ Jarolim P, Murray JL, Rubin HL, Taylor WM, Prchal JT, Ballas SK, Snyder LM, Chrobak L, Melrose WD, Brabec V, Palek J. Characterization of 13 novel band 3 gene defects in hereditary spherocytosis with band 3 deficiency. Blood. 1996 Dec 1;88(11):4366-74. PMID:8943874
- ↑ Eber SW, Gonzalez JM, Lux ML, Scarpa AL, Tse WT, Dornwell M, Herbers J, Kugler W, Ozcan R, Pekrun A, Gallagher PG, Schroter W, Forget BG, Lux SE. Ankyrin-1 mutations are a major cause of dominant and recessive hereditary spherocytosis. Nat Genet. 1996 Jun;13(2):214-8. PMID:8640229 doi:10.1038/ng0696-214
- ↑ Alloisio N, Texier P, Vallier A, Ribeiro ML, Morle L, Bozon M, Bursaux E, Maillet P, Goncalves P, Tanner MJ, Tamagnini G, Delaunay J. Modulation of clinical expression and band 3 deficiency in hereditary spherocytosis. Blood. 1997 Jul 1;90(1):414-20. PMID:9207478
- ↑ Miraglia del Giudice E, Vallier A, Maillet P, Perrotta S, Cutillo S, Iolascon A, Tanner MJ, Delaunay J, Alloisio N. Novel band 3 variants (bands 3 Foggia, Napoli I and Napoli II) associated with hereditary spherocytosis and band 3 deficiency: status of the D38A polymorphism within the EPB3 locus. Br J Haematol. 1997 Jan;96(1):70-6. PMID:9012689
- ↑ Dhermy D, Galand C, Bournier O, Boulanger L, Cynober T, Schismanoff PO, Bursaux E, Tchernia G, Boivin P, Garbarz M. Heterogenous band 3 deficiency in hereditary spherocytosis related to different band 3 gene defects. Br J Haematol. 1997 Jul;98(1):32-40. PMID:9233560
- ↑ Iwase S, Ideguchi H, Takao M, Horiguchi-Yamada J, Iwasaki M, Takahara S, Sekikawa T, Mochizuki S, Yamada H. Band 3 Tokyo: Thr837-->Ala837 substitution in erythrocyte band 3 protein associated with spherocytic hemolysis. Acta Haematol. 1998;100(4):200-3. PMID:9973643 doi:40904
- ↑ Lima PR, Sales TS, Costa FF, Saad ST. Arginine 490 is a hot spot for mutation in the band 3 gene in hereditary spherocytosis. Eur J Haematol. 1999 Nov;63(5):360-1. PMID:10580570
- ↑ Ribeiro ML, Alloisio N, Almeida H, Gomes C, Texier P, Lemos C, Mimoso G, Morle L, Bey-Cabet F, Rudigoz RC, Delaunay J, Tamagnini G. Severe hereditary spherocytosis and distal renal tubular acidosis associated with the total absence of band 3. Blood. 2000 Aug 15;96(4):1602-4. PMID:10942416
- ↑ Yawata Y, Kanzaki A, Yawata A, Doerfler W, Ozcan R, Eber SW. Characteristic features of the genotype and phenotype of hereditary spherocytosis in the Japanese population. Int J Hematol. 2000 Feb;71(2):118-35. PMID:10745622
- ↑ Bracher NA, Lyons CA, Wessels G, Mansvelt E, Coetzer TL. Band 3 Cape Town (E90K) causes severe hereditary spherocytosis in combination with band 3 Prague III. Br J Haematol. 2001 Jun;113(3):689-93. PMID:11380459
- ↑ Lima PR, Baratti MO, Chiattone ML, Costa FF, Saad ST. Band 3Tambau: a de novo mutation in the AE1 gene associated with hereditary spherocytosis. Implications for anion exchange and insertion into the red blood cell membrane. Eur J Haematol. 2005 May;74(5):396-401. PMID:15813913 doi:10.1111/j.1600-0609.2004.00405.x
- ↑ Bruce LJ, Robinson HC, Guizouarn H, Borgese F, Harrison P, King MJ, Goede JS, Coles SE, Gore DM, Lutz HU, Ficarella R, Layton DM, Iolascon A, Ellory JC, Stewart GW. Monovalent cation leaks in human red cells caused by single amino-acid substitutions in the transport domain of the band 3 chloride-bicarbonate exchanger, AE1. Nat Genet. 2005 Nov;37(11):1258-63. Epub 2005 Oct 9. PMID:16227998 doi:10.1038/ng1656
- ↑ Schneider ML, Post CB. Solution structure of a band 3 peptide inhibitor bound to aldolase: a proposed mechanism for regulating binding by tyrosine phosphorylation. Biochemistry. 1995 Dec 26;34(51):16574-84. PMID:8527430
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