ABCG8 p.Gly574Glu
| Predicted by SNAP2: | A: D (91%), C: D (95%), D: D (95%), E: D (95%), F: D (95%), H: D (95%), I: D (95%), K: D (95%), L: D (95%), M: D (95%), N: D (95%), P: D (95%), Q: D (95%), R: D (95%), S: D (85%), T: D (95%), V: D (95%), W: D (95%), Y: D (95%), |
| Predicted by PROVEAN: | A: N, C: D, D: D, E: D, F: D, H: D, I: D, K: D, L: D, M: D, N: D, P: D, Q: D, R: D, S: D, T: D, V: D, W: D, Y: D, |
[switch to compact view]
Comments [show]
None has been submitted yet.
[hide] Mutational studies of G553 in TM5 of ABCG2: a resi... Biochemistry. 2006 Apr 25;45(16):5251-60. Polgar O, Ozvegy-Laczka C, Robey RW, Morisaki K, Okada M, Tamaki A, Koblos G, Elkind NB, Ward Y, Dean M, Sarkadi B, Bates SE
Mutational studies of G553 in TM5 of ABCG2: a residue potentially involved in dimerization.
Biochemistry. 2006 Apr 25;45(16):5251-60., 2006-04-25 [PMID:16618113]
Abstract [show]
ABCG2 is an ATP-binding cassette half-transporter conferring resistance to chemotherapeutic agents such as mitoxantrone, irinotecan, and flavopiridol. With its one transmembrane and one ATP-binding domain, ABCG2 is thought to homodimerize for function. One conserved region potentially involved in dimerization is a three-amino acid sequence in transmembrane segment 5 (residues 552-554). Mutations in the corresponding residues in the Drosophila white protein (an orthologue of ABCG2) are thought to disrupt heterodimerization. We substituted glycine 553 with leucine (G553L) followed by stable transfection in HEK 293 cells. The mutant was not detectable on the cell surface, and markedly reduced protein expression levels were observed by immunoblotting. A deficiency in N-linked glycosylation was suggested by a reduction in molecular mass compared to that of the 72 kDa wild-type ABCG2. Similar results were observed with the G553E mutant. Confocal microscopy demonstrated mostly ER localization of the G553L mutant in HEK 293 cells, even when coexpressed with the wild-type protein. Despite its altered localization, the G553L and G553E mutants were cross-linked using amine-reactive cross-linkers with multiple arm lengths, suggesting that the monomers are in the proximity of each other but are unable to complete normal trafficking. Interestingly, when expressed in Sf9 insect cells, G553L moves to the cell membrane but is unable to hydrolyze ATP or transport the Hoechst dye. Still, when coexpressed, the mutant interferes with the Hoechst transport activity of the wild-type protein. These data show that glycine 553 is important for protein trafficking and are consistent with, but do not yet prove, its involvement in ABCG2 homodimerization.
Comments [show]
None has been submitted yet.
No. Sentence Comment
229 Furthermore, the naturally occurring ABCG8 G574E mutant, carrying a mutation corresponding to phenylalanine 551 of ABCG2, was also characterized as interfering with dimerization.
X
ABCG8 p.Gly574Glu 16618113:229:43
status: NEW230 When the ABCG8 G574E mutant was coexpressed with wild-type ABCG5 in CHO-K1 cells, no protein in the position of a dimer was detected on native gels (37).
X
ABCG8 p.Gly574Glu 16618113:230:15
status: NEW[hide] Genetic basis of sitosterolemia. Curr Opin Lipidol. 2001 Apr;12(2):141-9. Lee MH, Lu K, Patel SB
Genetic basis of sitosterolemia.
Curr Opin Lipidol. 2001 Apr;12(2):141-9., [PMID:11264985]
Abstract [show]
The molecular mechanisms regulating the amount of dietary cholesterol retained by the body, as well as the body's ability to exclude other dietary sterols selectively, are poorly understood. An average Western diet will contain approximately 250-500 mg of dietary cholesterol and approximately 200-400 mg of non-cholesterol sterols, of which plant sterols are the major constituents. Approximately 50-60% of dietary cholesterol is absorbed and retained by the normal human body, but less than 1% of the non-cholesterol sterols are retained. There thus exists a subtle mechanism that allows the body to distinguish between cholesterol and non-cholesterol sterols. In sitosterolemia, a rare autosomal recessive disorder, affected individuals hyperabsorb and retain not only cholesterol but also all other sterols, including plant and shellfish sterols from the intestine. Consequently, patients with this disease have very high levels of plant sterols in the plasma, and develop tendon and tuberous xanthomas, accelerated atherosclerosis, and premature coronary artery disease. The STSL locus has been mapped to human chromosome 2p21. Mutations in two tandem ABC genes, ABCG5 and ABCG8, encoding sterolin-1 and -2, respectively, are now known to be mutant in sitosterolemia. The identification of these genes should now lead to a better understanding of the molecular mechanism(s) governing the highly selective absorption and retention of cholesterol by the body. Indeed, it is the very existence of this disease that has given credence to the hypothesis that there is a molecular pathway that regulates dietary cholesterol absorption and sterol excretion by the body.
Comments [show]
None has been submitted yet.
No. Sentence Comment
108 Mutations in ABCG5 and ABCG8 in sitosterolemia Patients Nationality/ethnicity ABCG5 ABCG8 4 US/Caucasian Arg412X Trp361X 9 US/Caucasian Arg543Ser Gln172X 56* US/Caucasian Tyr658X Trp361X 60 US/Caucasian Trp361X ± 90* US/Caucasian Trp361X Trp361X 94 US/Caucasian Trp361X Arg184His 120 US/Caucasian Leu501Pro Trp361X 125 US/Caucasian Trp361X Trp361X 128 US/Caucasian Leu596Arg ± 32 SA Caucasian Arg121X Arg121X 98 Dutch Caucasian Gly574Glu Trp361X 102* US/Caucasian Trp361X ± 135 Columbian/Caucasian Trp536X Trp536X 20 Finnish Trp361X Trp361X 116 Norwegian Trp36X Trp361X 84* US/Amish/Mennonite Gly574Arg Gly574Arg 108 US/Amish/Mennonite Gly574Arg Gly574Arg 25 SA/Asian Arg243X Arg243X 40 Japanese Arg419His Arg419His 46 Japanese Arg389His Arg389His 63 Japanese del Exon 3 del Exon 3 113 Japanese Arg389His Arg389His 132 Japanese Arg419His ± 140 Japanese Arg408X Arg408X 146 Japanese Arg389His Arg389His 157 US/Caucasian Arg419Pro Arg419Pro 15 US/Caucasian ± ± 143 SA/Indian Asian ± ± Arg121X Arg164X 149 African American Glu145Gln ± 1* German/Swiss Trp361X Trp361X 2* US/Amish Gly574Arg Gly574Arg 3* US/Caucasian Trp361X Tyr658X 5* US/Caucasian Trp361X Arg412X 6* US/Caucasian Leu596Arg ± 7 US/Hispanic Arg412X del547C4191X 8* NZ/Caucasian Trp361X ± 4 Chinese Arg263Gln Pro231Thr 9 Chinese Arg408X ± This is a compilation of the mutations identified in ABCG5 and ABCG8.
X
ABCG8 p.Gly574Glu 11264985:108:438
status: VERIFIED[hide] Mutations in the human ATP-binding cassette transp... Hum Mutat. 2002 Aug;20(2):151. Heimerl S, Langmann T, Moehle C, Mauerer R, Dean M, Beil FU, von Bergmann K, Schmitz G
Mutations in the human ATP-binding cassette transporters ABCG5 and ABCG8 in sitosterolemia.
Hum Mutat. 2002 Aug;20(2):151., [PMID:12124998]
Abstract [show]
Phytosterolemia or Sitosterolemia is a rare autosomal recessive disorder characterized by highly elevated plasma levels of plant sterols and cholesterol as a consequence of hyperabsorption and impaired biliary secretion of sterols. The disease is caused by mutations in two half size ATP-binding cassette transporters, ABCG5 and ABCG8. We have analyzed the genomic sequence of ABCG5 and ABCG8 in five well-characterized patients with Sitosterolemia. In the first patient we found a heterozygous mutation in exon 8 of the ABCG5 gene leading to a premature termination of the protein (Arg408Ter). This German patient is the first European showing a mutation of the ABCG5 gene. In a second patient we found a novel heterozygous mutation in exon 5 of ABCG8 (c.584T>A; Leu195Gln). Both patients were heterozygous for the identified mutation, but no mutation could be identified on the other chromosome. In three further analyzed patients we found mutations in exons 7, 9 and 11 of the ABCG8 gene, respectively, of which two result in a premature termination signal for translation products. One of these patients was compound heterozygous (Trp361Ter and Arg412Ter), the other was homozygous for Trp361Ter. The third patient was homozygous for an amino acid exchange (Gly574Arg). In conclusion this report describes one novel mutation affecting a highly conserved amino acid and two previously identified mutations in the ABCG8 gene. In addition, we identified for the first time a mutation in the ABCG5 gene of a European Sitosterolemia patient.
Comments [show]
None has been submitted yet.
No. Sentence Comment
77 C Y658stop R121stop R164stop Q172stop R184H L195Q P231T G574R G574E L572P L596R N ABC B S AA R263Q E146Q R405H R543S W536stop R412stop W361stop C R419P R419H R408stop R398H N437K R550S R243stop N ABCG5 ABCG8 S B A IVS1 -2A>G Del547C>191stop L501P L596R 1568_1572delTCTTT 1798_1800delTTC Del Exon 3 C336-337insA 201 * Signature 250 ABCG1 Q..EKDEG.R REMVKEILTA L GLLSCANTR TGS.... .LS GGQR KRLAIA ABCG2 ATTMTNHE.K NERINRVIEE L GLDKVADSK VGTQFIR GVS GGER KRTSIG ABCG4 S..EKQEV.K KELVTEILTA L GLMSCSHTR TAL.... .LS GGQR KRLAIA ABCG5 R..RGNPGSF QKKVEAVMAE L SLSHVADRL IGNYSLG GIS TGER RRVSIA ABCG8 PRTFSQAQ.R DKRVEDVIAE L RLRQCADTR VGNMYVR GLS GGER RRVSIG Figure 2: Alignment of the human ABC transporters G1, G2, G4, G5 and G8. The amino acid change Leu195Gln in ABCG8 found in patient 2 is located intracellularly between the Walker A and the Signature C-motif.
X
ABCG8 p.Gly574Glu 12124998:77:62
status: VERIFIED[hide] Missense mutations in ABCG5 and ABCG8 disrupt hete... J Biol Chem. 2004 Jun 4;279(23):24881-8. Epub 2004 Mar 30. Graf GA, Cohen JC, Hobbs HH
Missense mutations in ABCG5 and ABCG8 disrupt heterodimerization and trafficking.
J Biol Chem. 2004 Jun 4;279(23):24881-8. Epub 2004 Mar 30., 2004-06-04 [PMID:15054092]
Abstract [show]
Mutations in ABCG5 (G5) or ABCG8 (G8) cause sitosterolemia, an autosomal recessive disease characterized by sterol accumulation and premature atherosclerosis. G5 and G8 are ATP-binding cassette (ABC) half-transporters that must heterodimerize to move to the apical surface of cells. We examined the role of N-linked glycans in the formation of the G5/G8 heterodimer to gain insight into the determinants of folding and trafficking of these proteins. Site-directed mutagenesis revealed that two asparagine residues (Asn(585) and Asn(592)) are glycosylated in G5 and that G8 has a single N-linked glycan attached to Asn(619). N-Linked glycosylation of G8 was required for efficient trafficking of the G5/G8 heterodimer, but mutations that abolished glycosylation of G5 did not prevent trafficking of the heterodimer. Both G5 and G8 are bound by the lectin chaperone, calnexin, suggesting that the calnexin cycle may facilitate folding of the G5/G8 heterodimer. To determine the effects of 13 disease-causing missense mutations in G5 and G8 on formation and trafficking of the G5/G8 heterodimer, mutant forms of the half-transporters were expressed in CHO-K1 cells. All 13 mutations reduced trafficking of the G5/G8 heterodimer from the endoplasmic reticulum to the Golgi complex, and most prevented the formation of stable heterodimers between G5 and G8. We conclude that the majority of the molecular defects in G5 and G8 that cause sitosterolemia impair transport of the sterol transporter to the cell surface.
Comments [show]
None has been submitted yet.
No. Sentence Comment
198 Three exceptions, L596R, G574E, and G574R in G8, result in the substitution of charged for neutral amino acids.
X
ABCG8 p.Gly574Glu 15054092:198:25
status: VERIFIED197 Three exceptions, L596R, G574E, and G574R in G8, result in the substitution of charged for neutral amino acids.
X
ABCG8 p.Gly574Glu 15054092:197:25
status: NEW[hide] Two genes that map to the STSL locus cause sitoste... Am J Hum Genet. 2001 Aug;69(2):278-90. Epub 2001 Jul 9. Lu K, Lee MH, Hazard S, Brooks-Wilson A, Hidaka H, Kojima H, Ose L, Stalenhoef AF, Mietinnen T, Bjorkhem I, Bruckert E, Pandya A, Brewer HB Jr, Salen G, Dean M, Srivastava A, Patel SB
Two genes that map to the STSL locus cause sitosterolemia: genomic structure and spectrum of mutations involving sterolin-1 and sterolin-2, encoded by ABCG5 and ABCG8, respectively.
Am J Hum Genet. 2001 Aug;69(2):278-90. Epub 2001 Jul 9., [PMID:11452359]
Abstract [show]
Sitosterolemia is a rare autosomal recessive disorder characterized by (a) intestinal hyperabsorption of all sterols, including cholesterol and plant and shellfish sterols, and (b) impaired ability to excrete sterols into bile. Patients with this disease have expanded body pools of cholesterol and very elevated plasma plant-sterol species and frequently develop tendon and tuberous xanthomas, accelerated atherosclerosis, and premature coronary artery disease. In previous studies, we have mapped the STSL locus to human chromosome 2p21. Recently, we reported that a novel member of the ABC-transporter family, named "sterolin-1" and encoded by ABCG5, is mutated in 9 unrelated families with sitosterolemia; in the remaining 25 families, no mutations in sterolin-1 could be identified. We identified another ABC transporter, located <400 bp upstream of sterolin-1, in the opposite orientation. Mutational analyses revealed that this highly homologous protein, termed "sterolin-2" and encoded by ABCG8, is mutated in the remaining pedigrees. Thus, two highly homologous genes, located in a head-to-head configuration on chromosome 2p21, are involved as causes of sitosterolemia. These studies indicate that both sterolin-1 and sterolin-2 are indispensable for the regulation of sterol absorption and excretion. Identification of sterolin-1 and sterolin-2 as critical players in the regulation of dietary-sterol absorption and excretion identifies a new pathway of sterol transport.
Comments [show]
None has been submitted yet.
No. Sentence Comment
134 A human full- Table 2 Compilation of Mutations in ABCG5 and ABCG8 PATIENT (NATIONALITY/ETHNICITY) MUTATIONS IN ABCG5a ABCG8b 4 (U.S./white) Trp361X (1173GrA) / Arg412X (1324CrT) 9 (U.S./white) Arg543Ser (1719GrT) / Gln172X (604CrT) 56c (U.S./white) Trp361X (1173GrA) / Tyr658X (2064CrG) 60 (U.S./white) Trp361X (1173GrA) / IVS1 -2 ArG 90c (U.S./white) Trp361X (1173GrA) / Trp361X (1173GrA) 94 (U.S./white) Trp361X (1173GrA) / Arg184His (641GrA) 120 (U.S./white) Trp361X (1173GrA) / Leu501Pro (1592TrC) 125 (U.S./white) Trp361X (1173GrA) / Trp361X (1173GrA) 128 (U.S./white) Leu596Arg (1877TrG) / IVS1 -2 ArG 172 (U.S./white) Trp361X (1173GrA) / Tyr658Stop (2064CrG) 166c (U.S./white) Trp361X (1173GrA) / Arg412X (1324CrT) 32 (SA/white) Arg121X (451CrT) / Arg121X (451CrT) 98 (Dutch/white) Trp361X (1173GrA) / Gly574Glu (1811GrA) 102c,d (U.S./white) Trp361X (1173GrA) / … 84c (U.S./Amish-Mennonite) Gly574Arg (1810GrA) / Gly574Arg (1810GrA) 108c (U.S./Amish-Mennonite) Gly574Arg (1810GrA) / Gly574Arg (1810GrA) 135 (Columbian/white) Trp536X (1698GrA) / Trp536X (1698GrA) 175 (French) 1798_1800delTTC / Arg405His (1304GrA) 20 (Finnish) Trp361X (1173GrA) / Trp361X (1173GrA) 154 (Finnish) Trp361X (1173GrA) / … 116 (Norwegian) Trp361X (1173GrA) / Trp361X (1173GrA) 163 (Swedish) Trp361X (1173GrA) / Leu572Pro (1805TrC) 15 (U.S./white) 1568_1572delTCTTT / IVS1 -2 ArG 143 (SA/Asian) Arg164X (580CrT) / Arg121X (451CrT) 25 (SA/Asian) Arg243X (876CrT) / Arg243X (876CrT) 40 (Japanese) Arg419His (1396GrA) / Arg419His (1396GrA) 46 (Japanese) Arg389His (1306GrA) / Arg389His (1306GrA) 63 (Japanese) del exon 3 / del exon 3 113 (Japanese) Arg389His (1306GrA) / Arg389His (1306GrA) 132 (Japanese) Arg419His (1396GrC) / Arg550Ser (1790ArC) 140 (Japanese) Arg408X (1362CrT) / Arg408X (1362CrT) 146 (Japanese) Arg389His (1306GrA) / Arg389His (1306GrA) 157 (U.S./white) Arg419Pro (1396GrC) / Arg419Pro (1396GrC) 149 (African American) Glu146Gln (576GrC) / … 1c,e (German/Swiss) Trp361X / Trp361X 2c,e (U.S./Amish) Gly574Arg / Gly574Arg 3c,e (U.S./white) Trp361X / Tyr658X 5c,d (U.S./white) Trp361X / Arg412X 6c,e (U.S./white) Leu596Arg / … 7d (U.S./Hispanic) Arg412X / del547Cr191X 8c,e (New Zealand/white) Trp361X / … 4e (Chinese) Arg263Gln / Pro231Thr 9e (Chinese) Arg408X / … a GenBank accession number AF312715.
X
ABCG8 p.Gly574Glu 11452359:134:812
status: NEWX
ABCG8 p.Gly574Glu 11452359:134:824
status: NEW146 of Alleles Frequency Restriction-Enzyme Recognition ABCG5: Glu146Gln 1 .05 Gain of AlwNI Arg243X 2 .10 Gain of AlwNI Arg389His 6 .30 Loss of BstUI Arg408X 3 .15 Loss of AvaI Arg419Pro 2 .10 Loss of BstUI Arg419His 3 .15 Loss of BstUI del exon 3 2 .10 … Arg550Ser 1 .05 … Total 20 ABCG8: Arg121X 3 .061 Gain of DdeI Arg164stop 1 .020 … Gln172X 1 .020 Gain of BfaI Arg184His 1 .020 Gain of NalIII Pro231Thr 1 .020 Loss of NlaIV Arg263Gln 1 .020 Gain of AluI Trp361X 19 .39 … Arg405His 1 .020 … Arg412X 3 .061 Gain of DdeI Leu501Pro 1 .020 Loss of AluI Trp536X 2 .041 Gain of AhdI Arg543Ser 1 .020 … Leu572Pro 1 .020 Gain of FauI Gly574Glu 1 .020 Loss of MspI Gly574Arg 4 .082 Loss of MspI Leu596Arg 1 .020 Gain of MspI Tyr658X 2 .041 Gain of SfcI IVS1 -2ArG 3 .061 Gain of BtgI 1798_1800delTTC 1 .020 … 1568_1572delTCTTT 1 .020 … Total 49 Mutations of Sterolin-2/ABCG8 as the Cause of Sitosterolemia Information on the exon/intron boundaries was used to screen probands, including those known to be mutated for sterolin-1, and to compare them to normal controls.
X
ABCG8 p.Gly574Glu 11452359:146:663
status: NEW