ENTRY       hsa03430                    Pathway
NAME        Mismatch repair - Homo sapiens (human)
DESCRIPTION DNA mismatch repair (MMR) is a highly conserved biological pathway that plays a key role in maintaining genomic stability. MMR corrects DNA mismatches generated during DNA replication, thereby preventing mutations from becoming permanent in dividing cells. MMR also suppresses homologous recombination and was recently shown to play a role in DNA damage signaling. Defects in MMR are associated with genome-wide instability, predisposition to certain types of cancer including HNPCC, resistance to certain chemotherapeutic agents, and abnormalities in meiosis and sterility in mammalian systems.
            The Escherichia coli MMR pathway has been extensively studied and is well characterized. In E. coli, the mismatch-activated MutS-MutL-ATP complex licenses MutH to incise the nearest unmethylated GATC sequence. UvrD and an exonuclease generate a gap. This gap is filled by pol III and DNA ligase. The GATC sites are then methylated by Dam. Several human MMR proteins have been identified based on their homology to E. coli MMR proteins. These include human homologs of MutS and MutL. Although E. coli MutS and MutL proteins are homodimers, human MutS and MutL homologs are heterodimers. The role of hemimethylated dGATC sites as a signal for strand discrimination is not conserved from E. coli to human. Human MMR is presumed to be nick-directed in vivo, and is thought to discriminate daughter and template strands using a strand-specific nick.
CLASS       Genetic Information Processing; Replication and repair
PATHWAY_MAP hsa03430  Mismatch repair
NETWORK     nt06503  Mismatch repair
  ELEMENT   N01432  Mismatch repair
DBLINKS     GO: 0006298
ORGANISM    Homo sapiens (human) [GN:hsa]
GENE        6742  SSBP1; single stranded DNA binding protein 1 [KO:K03111]
            5395  PMS2; PMS1 homolog 2, mismatch repair system component [KO:K10858]
            4292  MLH1; mutL homolog 1 [KO:K08734]
            2956  MSH6; mutS homolog 6 [KO:K08737]
            4436  MSH2; mutS homolog 2 [KO:K08735]
            4437  MSH3; mutS homolog 3 [KO:K08736]
            27030  MLH3; mutL homolog 3 [KO:K08739]
            5981  RFC1; replication factor C subunit 1 [KO:K10754]
            5984  RFC4; replication factor C subunit 4 [KO:K10755]
            5982  RFC2; replication factor C subunit 2 [KO:K10755]
            5985  RFC5; replication factor C subunit 5 [KO:K10756]
            5983  RFC3; replication factor C subunit 3 [KO:K10756]
            5111  PCNA; proliferating cell nuclear antigen [KO:K04802]
            9156  EXO1; exonuclease 1 [KO:K10746] [EC:3.1.-.-]
            6117  RPA1; replication protein A1 [KO:K07466]
            6118  RPA2; replication protein A2 [KO:K10739]
            6119  RPA3; replication protein A3 [KO:K10740]
            29935  RPA4; replication protein A4 [KO:K10741]
            5424  POLD1; DNA polymerase delta 1, catalytic subunit [KO:K02327] [EC:2.7.7.7]
            5425  POLD2; DNA polymerase delta 2, accessory subunit [KO:K02328]
            10714  POLD3; DNA polymerase delta 3, accessory subunit [KO:K03504]
            57804  POLD4; DNA polymerase delta 4, accessory subunit [KO:K03505]
            3978  LIG1; DNA ligase 1 [KO:K10747] [EC:6.5.1.1 6.5.1.6 6.5.1.7]
REFERENCE   PMID:16612326
  AUTHORS   Jiricny J.
  TITLE     The multifaceted mismatch-repair system.
  JOURNAL   Nat Rev Mol Cell Biol 7:335-46 (2006)
            DOI:10.1038/nrm1907
REFERENCE   PMID:18157157
  AUTHORS   Li GM.
  TITLE     Mechanisms and functions of DNA mismatch repair.
  JOURNAL   Cell Res 18:85-98 (2008)
            DOI:10.1038/cr.2007.115
REFERENCE   PMID:11920679
  AUTHORS   Marti TM, Kunz C, Fleck O.
  TITLE     DNA mismatch repair and mutation avoidance pathways.
  JOURNAL   J Cell Physiol 191:28-41 (2002)
            DOI:10.1002/jcp.10077
REFERENCE   PMID:11436301
  AUTHORS   Ikejima M, Shimada T.
  TITLE     [Molecular mechanism of mismatch repair]
  JOURNAL   Tanpakushitsu Kakusan Koso 46:1124-9 (2001)
REL_PATHWAY hsa05210  Colorectal cancer
KO_PATHWAY  ko03430
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