Characterization of the Interactome of the Human MutL Homologues MLH1, PMS1, and PMS2

• Published in: The Journal of biological chemistry 2007-02, Vol.282 (5), p.2976-2986
• Main Authors: Cannavo, Elda, Gerrits, Bertran, Marra, Giancarlo, Schlapbach, Ralph, Jiricny, Josef
• Format: Article
• Language: English
• Subjects: Adaptor Proteins, Signal Transducing; Adenosine Triphosphatases - genetics; Adenosine Triphosphatases - metabolism; Animals; Base Pair Mismatch; Carrier Proteins - genetics; Carrier Proteins - metabolism; Cell Line; DNA Repair Enzymes - genetics; DNA Repair Enzymes - metabolism; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Genetic Vectors; Humans; Methylnitronitrosoguanidine; Mismatch Repair Endonuclease PMS2; MutL Protein Homolog 1; MutL Proteins; Neoplasm Proteins - genetics; Neoplasm Proteins - isolation & purification; Neoplasm Proteins - metabolism; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; Recombinant Proteins - metabolism
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M609989200

Postreplicative mismatch repair (MMR) involves the concerted action of at least 20 polypeptides. Although the minimal human MMR system has recently been reconstituted in vitro, genetic evidence from different eukaryotic organisms suggests that some steps of the MMR process may be carried out by more than one protein. Moreover, MMR proteins are involved also in other pathways of DNA metabolism, but their exact role in these processes is unknown. In an attempt to gain novel insights into the function of MMR proteins in human cells, we searched for interacting partners of the MutL homologues MLH1 and PMS2 by tandem affinity purification and of PMS1 by large scale immunoprecipitation. In addition to proteins known to interact with the MutL homologues during MMR, mass spectrometric analyses identified a number of other polypeptides, some of which bound to the above proteins with very high affinity. Whereas some of these interactors may represent novel members of the mismatch repairosome, others appear to implicate the MutL homologues in biological processes ranging from intracellular transport through cell signaling to cell morphology, recombination, and ubiquitylation.