Related Experiment Videos
The human PMS2L proteins do not interact with hMLH1, a major DNA mismatch repair protein
E Kondo1, A Horii, S Fukushige
1Department of Molecular Pathology, Tohoku University School of Medicine, Sendai, Miyagi, 980-8575, Japan.
Abstract:
The human PMS2 gene encodes one of the bacterial mutL homologs that is associated with hereditary nonpolyposis colorectal cancer (HNPCC). One of the interesting features of the hPMS2 gene is that it is part of a multiple gene family which is localized on chromosome bands 7p22, 7p12-p13, 7q11, and 7q22. Here we report four newly identified hPMS2-like (PMS2L) genes. All four novel members of the PMS2L gene family encode relatively short polypeptides composed of the amino-terminal portion of hPMS2 and are expressed ubiquitously except in the heart. To clarify whether the PMS2L polypeptides contribute to the DNA mismatch repair (MMR) pathway through an interaction with hMLH1, we have performed a yeast two-hybrid assay and an immunoprecipitation study using an hPMS2 mutant cell line, HEC-1-A. Our results clearly indicate that hMLH1 does not interact with two representative PMS2Ls, whereas the carboxyl-terminal portion of hPMS2, not the amino-terminal portion, does interact with hMLH1. Thus, PMS2Ls are not likely to participate in the MMR pathway through association with hMLH1; they must play some other roles in the living cells.
Insights
Four new hPMS2-like (PMS2L) genes were identified. These PMS2L proteins do not interact with hMLH1, suggesting they do not participate in DNA mismatch repair and likely have other cellular functions.
Area of Science:
- Genetics
- Molecular Biology
- Cancer Research
Background:
- The human PMS2 gene is crucial for DNA mismatch repair (MMR) and linked to hereditary nonpolyposis colorectal cancer (HNPCC).
- The hPMS2 gene belongs to a multigene family located on chromosome 7.
Purpose of the Study:
- To identify and characterize novel hPMS2-like (PMS2L) genes.
- To investigate the potential role of PMS2L polypeptides in the DNA mismatch repair pathway through interaction with hMLH1.
Main Methods:
- Identification of four new PMS2L genes.
- Yeast two-hybrid assay and immunoprecipitation studies using the HEC-1-A cell line.
- Analysis of protein-protein interactions between PMS2L, hPMS2, and hMLH1.
Main Results:
- Four novel PMS2L genes were identified, encoding short polypeptides from the amino-terminal portion of hPMS2.
- PMS2L polypeptides are ubiquitously expressed, except in the heart.
- hMLH1 does not interact with representative PMS2L proteins, but interacts with the carboxyl-terminal portion of hPMS2.
Conclusions:
- PMS2L proteins are unlikely to be involved in the DNA mismatch repair pathway via association with hMLH1.
- The identified PMS2L genes likely serve distinct, yet unknown, roles in cellular functions.