XB-ART-20411Nucleic Acids Res December 25, 1994; 22 (25): 5723-8.
Show Gene links Show Anatomy links
Cloning and expression of the Xenopus and mouse Msh2 DNA mismatch repair genes.
Bacterial MutS protein and its yeast and human homologs MSH2 trigger the mismatch repair process by their initial binding to mispaired and unpaired bases in DNA. We describe the cloning and sequencing of genes from Xenopus laevis and Mus musculus encoding the homolog of the Saccharomyces cerevisiae MSH2 (the major DNA mismatch binding protein). Mutations in the human homolog of this gene have recently been implicated in microsatellite instability and DNA mismatch repair deficiency in tumour cells from patients with the most common hereditary predisposition to cancer (Lynch syndrome, or hereditary non-polyposis colorectal cancer, HNPCC), as well as in a significant percentage of sporadic tumours. Expression of the amphibian and murine Msh2 gene in different tissues appears to be ubiquitous. The Xenopus gene is highly expressed in eggs, a model system for the biochemistry of DNA mismatch repair. Expression of the murine gene is low in all tissues examined, and is relatively high in a rapidly dividing cell line. These data are suggestive of a role for MSH2 during DNA replication.
PubMed ID: 7838728
PMC ID: PMC310139
Article link: Nucleic Acids Res
Species referenced: Xenopus laevis
Genes referenced: grhl2 msh2
Article Images: [+] show captions
|Figure 1. Comparison of the deduced amino acid sequences from all MSH2 homologs known today. Abbreviations are as follows: ScMSH2: pepddic sequence of MSH2 frum Zcercvistae (10); XMSH2: MSH2 &om X/anir, MMSH2: mouse MSH2; HMSH2: human MSH2 (25, 26) ., . indicate identical amino acids and conservative substitutions respectively; — corresponds to a gap in the aligned sequence. Position of the primers used in the PCR reactions are shown with arrows. Conserved protein domains are in boM: NTP-binding motifs A -D and DNAbinding domain (helix—turn—helix) HTH.|
|Figure 2. Transcription and translation in vitro of the Xmsh2 cDNA sequence. Synthesized proteins were analysed on 8% SDS—PAGE. As a centred we expressed the E.coli mutS gene, provided with a Kozak sequence and a nuclear localization signal (NLS) (N.de Wind, unpublished). Protein molecular weight markers are indicated on the left.|
|Figure 3. Northern blot analysis of Xenopus (A) and mouse (B) transcripts at different developmental stages and in various tissues from the adult animals. (A) 4 - 5 /ig of Xenopus poly(A)+ RNA were loaded in each lane. Positions of the transcripts hybridizing to the Xmsh2 probe (3.2 kb) and to rhe EFl-a control probe (1.6 kb) are indicated. The expression of the translation elongation factor EFl-a starts at the mid-blastula transition during development (50). (B) 10-30 /xg of mouse total RNA were loaded, electrophoresed and blotted, and rhe blot was hybridized to rhe Mmsh2 cDNA probe. GAPDH: glyceraldehyde phosphate dehydrogenase in RNA as an internal control.|
|Figure 4. Dendogram showing clustering relationships between rhe different MSH proteins, generated with the PILEUP program (37). Abbreviations are as follows: DUT-1: human DUT-1 (22), REP-3: mouse Rep-3 (21), SW14: S.pombe SW14 (20), MSH3: S.ccre\isiae MSH3 (11. 12), HMSH2: human HMSH2 (25. 26). MMSH2: mouse MMSH2, XMSH2: Xenopus XMSH2, MSH2: S.cerevisiae MSH2 (10), MutS (Ec). E.coli MutS (51), MutS (St): S.typhimurium MutS (52), MutS (Av): Azotobacter vinelandu MutS (53), HexA- S.pnaanoniae HexA (54), MSH1: S.cerevisiae MSH1 (10) and MSH4: S.cerevisiae MSH4 (23).|
References [+] :
Aaltonen, Clues to the pathogenesis of familial colorectal cancer. 1993, Pubmed