Human MSH2 binds to trinucleotide repeat DNA structures associated with neurodegenerative diseases.

The expansion of trinucleotide repeat sequences is associated with several neurodegenerative diseases. The mechanism of this expansion is unknown but may involve slipped-strand structures where adjacent rather than perfect complementary sequences of a trinucleotide repeat become paired. Here, we have studied the interaction of the human mismatch repair protein MSH2 with slipped-strand structures formed from a triplet repeat sequence in order to address the possible role of MSH2 in trinucleotide expansion. Genomic clones of the myotonic dystrophy locus containing disease-relevant lengths of (CTG)n x (CAG)n triplet repeats were examined. We have constructed two types of slipped-strand structures by annealing complementary strands of DNA containing: (i) equal numbers of trinucleotide repeats (homoduplex slipped structures or S-DNA) or (ii) different numbers of repeats (heteroduplex slipped intermediates or SI-DNA). SI-DNAs having an excess of either CTG or CAG repeats were structurally distinct and could be separated electrophoretically and studied individually. Using a band-shift assay, the MSH2 was shown to bind to both S-DNA and SI-DNA in a structure-specific manner. The affinity of MSH2 increased with the length of the repeat sequence. Furthermore, MSH2 bound preferentially to looped-out CAG repeat sequences, implicating a strand asymmetry in MSH2 recognition. Our results are consistent with the idea that MSH2 may participate in trinucleotide repeat expansion via its role in repair and/or recombination.

[1]  M. Radman,et al.  The barrier to recombination between Escherichia coli and Salmonella typhimurium is disrupted in mismatch-repair mutants , 1989, Nature.

[2]  R. Sinden,et al.  Mismatch repair in Escherichia coli enhances instability of (CTG)n triplet repeats from human hereditary diseases. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[3]  P. Modrich,et al.  Mispair specificity of methyl-directed DNA mismatch correction in vitro. , 1988, The Journal of biological chemistry.

[4]  R. Fishel,et al.  Purified human MSH2 protein binds to DNA containing mismatched nucleotides. , 1994, Cancer research.

[5]  M. Stratton,et al.  Instability of short tandem repeats (microsatellites) in human cancers , 1994, Nature Genetics.

[6]  Bert Vogelstein,et al.  Hypermutability and mismatch repair deficiency in RER+ tumor cells , 1993, Cell.

[7]  A. Datta,et al.  Mitotic crossovers between diverged sequences are regulated by mismatch repair proteins in Saccaromyces cerevisiae , 1996, Molecular and cellular biology.

[8]  P. Modrich,et al.  Isolation of an hMSH2-p160 heterodimer that restores DNA mismatch repair to tumor cells. , 1995, Science.

[9]  T. Petes,et al.  Palindromic sequences in heteroduplex DNA inhibit mismatch repair in yeast , 1989, Nature.

[10]  I. Mellon,et al.  Products of DNA mismatch repair genes mutS and mutL are required for transcription-coupled nucleotide-excision repair of the lactose operon in Escherichia coli. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[11]  R. Richards,et al.  Heritable unstable DNA sequences , 1992, Nature Genetics.

[12]  T. Kamp,et al.  Hairpin properties of single-stranded DNA containing a GC-rich triplet repeat: (CTG)15. , 1995, Nucleic acids research.

[13]  M. Zannis‐Hadjopoulos,et al.  A novel type of interaction between cruciform DNA and a cruciform binding protein from HeLa cells. , 1995, The EMBO journal.

[14]  R. Reenan,et al.  Interaction between mismatch repair and genetic recombination in Saccharomyces cerevisiae. , 1994, Genetics.

[15]  J. Jiricny,et al.  Different base/base mispairs are corrected with different efficiencies and specificities in monkey kidney cells , 1988, Cell.

[16]  R. Bollag,et al.  Formation of heteroduplex DNA during mammalian intrachromosomal gene conversion , 1992, Molecular and cellular biology.

[17]  V. Bohr,et al.  Gene specific DNA repair. , 1991, Carcinogenesis.

[18]  P. Modrich,et al.  Escherichia coli mutS-encoded protein binds to mismatched DNA base pairs. , 1986, Proceedings of the National Academy of Sciences of the United States of America.

[19]  D. Schaid,et al.  Sequence analysis of the fragile X trinucleotide repeat: implications for the origin of the fragile X mutation. , 1994, Human molecular genetics.

[20]  Robert I. Richards,et al.  Simple repeat DNA is not replicated simply , 1994, Nature Genetics.

[21]  C. Amemiya,et al.  Myotonic dystrophy mutation: an unstable CTG repeat in the 3' untranslated region of the gene. , 1992, Science.

[22]  S. Warren,et al.  Trinucleotide repeat expansion and human disease. , 1995, Annual review of genetics.

[23]  M. Marinus,et al.  Repair of DNA heteroduplexes containing small heterologous sequences in Escherichia coli. , 1992, Proceedings of the National Academy of Sciences of the United States of America.

[24]  R. Sinden,et al.  Preferential DNA secondary structure mutagenesis in the lagging strand of replication in E. coli , 1991, Nature.

[25]  S. Warren,et al.  Cryptic and polar variation of the fragile X repeat could result in predisposing normal alleles , 1994, Cell.

[26]  J. Griffith,et al.  Binding of mismatched microsatellite DNA sequences by the human MSH2 protein. , 1994, Science.

[27]  T. Kunkel,et al.  DNA loop repair by human cell extracts. , 1994, Science.

[28]  C. Boland,et al.  Transcription-Coupled Repair Deficiency and Mutations in Human Mismatch Repair Genes , 1996, Science.

[29]  E. Eichler,et al.  Length of uninterrupted CGG repeats determines instability in the FMR1 gene , 1994, Nature Genetics.

[30]  A. Marquis Gacy,et al.  Trinucleotide repeats that expand in human disease form hairpin structures in vitro , 1995, Cell.

[31]  R. Sinden,et al.  DNA structure, mutations, and human genetic disease. , 1992, Current opinion in biotechnology.

[32]  R. Sinden,et al.  Stability of triplet repeats of myotonic dystrophy and fragile X loci in human mutator mismatch repair cell lines , 1996, Human Genetics.

[33]  H. Zoghbi,et al.  Evidence for a mechanism predisposing to intergenerational CAG repeat instability in spinocerebellar ataxia type I , 1993, Nature Genetics.

[34]  C. Gaillard,et al.  Association of poly(CA).poly(TG) DNA fragments into four-stranded complexes bound by HMG1 and 2. , 1994, Science.

[35]  C. E. Pearson,et al.  Cruciform DNA binding protein in HeLa cell extracts. , 1994, Biochemistry.

[36]  G. Marsischky,et al.  hMSH2 forms specific mispair-binding complexes with hMSH3 and hMSH6. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[37]  Robin J. Leach,et al.  Mutations of a mutS homolog in hereditary nonpolyposis colorectal cancer , 1993, Cell.

[38]  R. Kolodner,et al.  The Saccharomyces cerevisiae Msh2 protein specifically binds to duplex oligonucleotides containing mismatched DNA base pairs and insertions. , 1995, Genes & development.

[39]  Keiichi Ohshima,et al.  Expansion and deletion of CTG repeats from human disease genes are determined by the direction of replication in E. coli , 1995, Nature Genetics.

[40]  N. Copeland,et al.  The human mutator gene homolog MSH2 and its association with hereditary nonpolyposis colon cancer , 1993, Cell.

[41]  R. Sinden,et al.  Alternative structures in duplex DNA formed within the trinucleotide repeats of the myotonic dystrophy and fragile X loci. , 1996, Biochemistry.

[42]  J. Essigmann,et al.  The mismatch-repair protein hMSH2 binds selectively to DNA adducts of the anticancer drug cisplatin. , 1996, Chemistry & biology.

[43]  D. Shibata,et al.  Genomic instability in repeated sequences is an early somatic event in colorectal tumorigenesis that persists after transformation , 1994, Nature Genetics.

[44]  Peter Beighton,et al.  de la Chapelle, A. , 1997 .

[45]  J. Jiricny,et al.  GTBP, a 160-kilodalton protein essential for mismatch-binding activity in human cells. , 1995, Science.

[46]  J. Jiricny,et al.  Mismatch-containing oligonucleotide duplexes bound by the E. coli mutS-encoded protein. , 1988, Nucleic acids research.

[47]  Chung-I Wu,et al.  Inequality in mutation rates of the two strands of DNA , 1987, Nature.

[48]  R. Kolodner,et al.  Identification of mismatch repair genes and their role in the development of cancer. , 1995, Current opinion in genetics & development.

[49]  R. Rothstein,et al.  A defect in mismatch repair in Saccharomyces cerevisiae stimulates ectopic recombination between homeologous genes by an excision repair dependent process. , 1990, Genetics.

[50]  B. P. Belotserkovskii,et al.  Polypropylene Tube Surfaces May Induce Denaturation and Multimerization of DNA , 1996, Science.

[51]  M. Meuth,et al.  Mutator phenotypes in human colorectal carcinoma cell lines. , 1994, Proceedings of the National Academy of Sciences of the United States of America.

[52]  G. Fox,et al.  DNA CTG triplet repeats involved in dynamic mutations of neurologically related gene sequences form stable duplexes. , 1995, Nucleic acids research.

[53]  M. Radman,et al.  Repair of a mismatch is influenced by the base composition of the surrounding nucleotide sequence. , 1987, Genetics.