Phenotypic consequences of mutations in the conserved motifs of the putative helicase domain of the human Cockayne syndrome group B gene

Meltem Muftuoglu; Rebecca Selzer; Jingsheng Tuo; Robert M Brosh; Vilhelm A Bohr

Phenotypic consequences of mutations in the conserved motifs of the putative helicase domain of the human Cockayne syndrome group B gene

Meltem Muftuoglu, Rebecca Selzer, Jingsheng Tuo, Robert M Brosh, Vilhelm A Bohr

Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

41 Citationer (Scopus)

Abstract

Udgivelsesdato: 2002-Jan-23

Originalsprog	Engelsk
Tidsskrift	Gene
Vol/bind	283
Udgave nummer	1-2
Sider (fra-til)	27-40
Antal sider	13
ISSN	0378-1119
Status	Udgivet - 2002
Udgivet eksternt	Ja

Bibliografisk note

Keywords: 4-Nitroquinoline-1-oxide; Amino Acid Motifs; Amino Acid Sequence; Cell Survival; Conserved Sequence; DNA Helicases; DNA Repair Enzymes; Dose-Response Relationship, Drug; Dose-Response Relationship, Radiation; Gene Expression Regulation; Humans; Immunoblotting; Mutation; Phenotype; Quinolones; RNA; Sequence Homology, Amino Acid; Transcription, Genetic; Transfection; Ultraviolet Rays

Citationsformater

@article{69d6d2c0664011de8bc9000ea68e967b,

title = "Phenotypic consequences of mutations in the conserved motifs of the putative helicase domain of the human Cockayne syndrome group B gene",

abstract = "Cockayne syndrome (CS) is a human genetic disorder characterized by several neurological and developmental abnormalities. Two genetic complementation groups, CS-A and CS-B, have been identified. The CSB protein belongs to helicase superfamily 2, and to the SWI/SNF family of proteins. The CSB protein is implicated in transcription-coupled repair (TCR), basal transcription and chromatin remodeling. In addition, CS cells undergo UV-induced apoptosis at much lower doses than normal cells. However, the molecular function of the CSB protein in these biological pathways has remained unclear. Evidence indicates that the integrity of the Walker A and B boxes (motifs I and II) are important for CSB function, but the functional significance of the helicase motifs Ia, III--IV has not been previously examined. In this study, single amino acid changes in highly conserved residues of helicase motifs Ia, III, V, VI and a second putative nucleotide-binding motif (NTB) of the CSB protein were generated by site-directed mutagenesis to analyze the genetic function of the CSB protein in survival, RNA synthesis recovery and apoptosis after UV treatment. The survival analysis of these CS-B mutant cell lines was also performed after treatment with the chemical carcinogen, 4-nitroquinoline-1-oxide (4-NQO). The lesions induced by UV light, cyclobutane pyrimidine dimers, are known to be repaired by TCR whereas the lesions induced by 4-NQO are repaired by global genome repair. The results of this study demonstrate that the point mutations in highly conserved residues of helicase motifs Ia, III, V and VI abolished the genetic function of the CSB protein in survival, RNA synthesis recovery and apoptosis after UV treatment. Similarly, the same mutants failed to complement the sensitivity toward 4-NQO. Thus, the integrity of these helicase motifs is important for the biological function of the CSB protein. On the contrary, a point mutation in a C-terminal, second, NTB motif of the CSB protein showed full complementation in the ability to repair damage induced by UV light or 4-NQO, suggesting that this motif is not important for the CSB repair function.",

author = "Meltem Muftuoglu and Rebecca Selzer and Jingsheng Tuo and Brosh, {Robert M} and Bohr, {Vilhelm A}",

note = "Keywords: 4-Nitroquinoline-1-oxide; Amino Acid Motifs; Amino Acid Sequence; Cell Survival; Conserved Sequence; DNA Helicases; DNA Repair Enzymes; Dose-Response Relationship, Drug; Dose-Response Relationship, Radiation; Gene Expression Regulation; Humans; Immunoblotting; Mutation; Phenotype; Quinolones; RNA; Sequence Homology, Amino Acid; Transcription, Genetic; Transfection; Ultraviolet Rays",

year = "2002",

language = "English",

volume = "283",

pages = "27--40",

journal = "Gene",

issn = "0378-1119",

publisher = "Elsevier",

number = "1-2",

}

TY - JOUR

T1 - Phenotypic consequences of mutations in the conserved motifs of the putative helicase domain of the human Cockayne syndrome group B gene

AU - Muftuoglu, Meltem

AU - Selzer, Rebecca

AU - Tuo, Jingsheng

AU - Brosh, Robert M

AU - Bohr, Vilhelm A

N1 - Keywords: 4-Nitroquinoline-1-oxide; Amino Acid Motifs; Amino Acid Sequence; Cell Survival; Conserved Sequence; DNA Helicases; DNA Repair Enzymes; Dose-Response Relationship, Drug; Dose-Response Relationship, Radiation; Gene Expression Regulation; Humans; Immunoblotting; Mutation; Phenotype; Quinolones; RNA; Sequence Homology, Amino Acid; Transcription, Genetic; Transfection; Ultraviolet Rays

PY - 2002

Y1 - 2002

N2 - Cockayne syndrome (CS) is a human genetic disorder characterized by several neurological and developmental abnormalities. Two genetic complementation groups, CS-A and CS-B, have been identified. The CSB protein belongs to helicase superfamily 2, and to the SWI/SNF family of proteins. The CSB protein is implicated in transcription-coupled repair (TCR), basal transcription and chromatin remodeling. In addition, CS cells undergo UV-induced apoptosis at much lower doses than normal cells. However, the molecular function of the CSB protein in these biological pathways has remained unclear. Evidence indicates that the integrity of the Walker A and B boxes (motifs I and II) are important for CSB function, but the functional significance of the helicase motifs Ia, III--IV has not been previously examined. In this study, single amino acid changes in highly conserved residues of helicase motifs Ia, III, V, VI and a second putative nucleotide-binding motif (NTB) of the CSB protein were generated by site-directed mutagenesis to analyze the genetic function of the CSB protein in survival, RNA synthesis recovery and apoptosis after UV treatment. The survival analysis of these CS-B mutant cell lines was also performed after treatment with the chemical carcinogen, 4-nitroquinoline-1-oxide (4-NQO). The lesions induced by UV light, cyclobutane pyrimidine dimers, are known to be repaired by TCR whereas the lesions induced by 4-NQO are repaired by global genome repair. The results of this study demonstrate that the point mutations in highly conserved residues of helicase motifs Ia, III, V and VI abolished the genetic function of the CSB protein in survival, RNA synthesis recovery and apoptosis after UV treatment. Similarly, the same mutants failed to complement the sensitivity toward 4-NQO. Thus, the integrity of these helicase motifs is important for the biological function of the CSB protein. On the contrary, a point mutation in a C-terminal, second, NTB motif of the CSB protein showed full complementation in the ability to repair damage induced by UV light or 4-NQO, suggesting that this motif is not important for the CSB repair function.

AB - Cockayne syndrome (CS) is a human genetic disorder characterized by several neurological and developmental abnormalities. Two genetic complementation groups, CS-A and CS-B, have been identified. The CSB protein belongs to helicase superfamily 2, and to the SWI/SNF family of proteins. The CSB protein is implicated in transcription-coupled repair (TCR), basal transcription and chromatin remodeling. In addition, CS cells undergo UV-induced apoptosis at much lower doses than normal cells. However, the molecular function of the CSB protein in these biological pathways has remained unclear. Evidence indicates that the integrity of the Walker A and B boxes (motifs I and II) are important for CSB function, but the functional significance of the helicase motifs Ia, III--IV has not been previously examined. In this study, single amino acid changes in highly conserved residues of helicase motifs Ia, III, V, VI and a second putative nucleotide-binding motif (NTB) of the CSB protein were generated by site-directed mutagenesis to analyze the genetic function of the CSB protein in survival, RNA synthesis recovery and apoptosis after UV treatment. The survival analysis of these CS-B mutant cell lines was also performed after treatment with the chemical carcinogen, 4-nitroquinoline-1-oxide (4-NQO). The lesions induced by UV light, cyclobutane pyrimidine dimers, are known to be repaired by TCR whereas the lesions induced by 4-NQO are repaired by global genome repair. The results of this study demonstrate that the point mutations in highly conserved residues of helicase motifs Ia, III, V and VI abolished the genetic function of the CSB protein in survival, RNA synthesis recovery and apoptosis after UV treatment. Similarly, the same mutants failed to complement the sensitivity toward 4-NQO. Thus, the integrity of these helicase motifs is important for the biological function of the CSB protein. On the contrary, a point mutation in a C-terminal, second, NTB motif of the CSB protein showed full complementation in the ability to repair damage induced by UV light or 4-NQO, suggesting that this motif is not important for the CSB repair function.

M3 - Journal article

C2 - 11867210

SN - 0378-1119

VL - 283

SP - 27

EP - 40

JO - Gene

JF - Gene

IS - 1-2

ER -