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Localisation Microscopy of Breast Epithelial ErbB-2 Receptors and Gap Junctions: Trafficking after γ-Irradiation, Neuregulin-1β, and Trastuzumab Application. Int J Mol Sci 2017; 18:ijms18020362. [PMID: 28208769 PMCID: PMC5343897 DOI: 10.3390/ijms18020362] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 01/28/2017] [Accepted: 01/30/2017] [Indexed: 12/28/2022] Open
Abstract
In cancer, vulnerable breast epithelium malignance tendency correlates with number and activation of ErbB receptor tyrosine kinases. In the presented work, we observe ErbB receptors activated by irradiation-induced DNA injury or neuregulin-1β application, or alternatively, attenuated by a therapeutic antibody using high resolution fluorescence localization microscopy. The gap junction turnover coinciding with ErbB receptor activation and co-transport is simultaneously recorded. DNA injury caused by 4 Gray of 6 MeV photon γ-irradiation or alternatively neuregulin-1β application mobilized ErbB receptors in a nucleograde fashion—a process attenuated by trastuzumab antibody application. This was accompanied by increased receptor density, indicating packing into transport units. Factors mobilizing ErbB receptors also mobilized plasma membrane resident gap junction channels. The time course of ErbB receptor activation and gap junction mobilization recapitulates the time course of non-homologous end-joining DNA repair. We explain our findings under terms of DNA injury-induced membrane receptor tyrosine kinase activation and retrograde trafficking. In addition, we interpret the phenomenon of retrograde co-trafficking of gap junction connexons stimulated by ErbB receptor activation.
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Lai Y, Budworth H, Beaver JM, Chan NLS, Zhang Z, McMurray CT, Liu Y. Crosstalk between MSH2-MSH3 and polβ promotes trinucleotide repeat expansion during base excision repair. Nat Commun 2016; 7:12465. [PMID: 27546332 PMCID: PMC4996945 DOI: 10.1038/ncomms12465] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 07/06/2016] [Indexed: 01/07/2023] Open
Abstract
Studies in knockout mice provide evidence that MSH2-MSH3 and the BER machinery promote trinucleotide repeat (TNR) expansion, yet how these two different repair pathways cause the mutation is unknown. Here we report the first molecular crosstalk mechanism, in which MSH2-MSH3 is used as a component of the BER machinery to cause expansion. On its own, pol β fails to copy TNRs during DNA synthesis, and bypasses them on the template strand to cause deletion. Remarkably, MSH2-MSH3 not only stimulates pol β to copy through the repeats but also enhances formation of the flap precursor for expansion. Our results provide direct evidence that MMR and BER, operating together, form a novel hybrid pathway that changes the outcome of TNR instability from deletion to expansion during the removal of oxidized bases. We propose that cells implement crosstalk strategies and share machinery when a canonical pathway is ineffective in removing a difficult lesion.
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Affiliation(s)
- Yanhao Lai
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, Florida 33199, USA
| | - Helen Budworth
- Life Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, 33R249, Berkeley, California 94720, USA
| | - Jill M. Beaver
- Biochemistry Ph.D. Program, Florida International University, 11200 SW 8th Street, Miami, Florida 33199, USA
| | - Nelson L. S. Chan
- Life Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, 33R249, Berkeley, California 94720, USA
| | - Zunzhen Zhang
- Department of Occupational and Environmental Health, Sichuan University West China School of Public Health, 16#, Section 3, Renmin Nan Lu, Chengdu, Sichuan 610041, China
| | - Cynthia T. McMurray
- Life Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, 33R249, Berkeley, California 94720, USA
| | - Yuan Liu
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, Florida 33199, USA
- Biochemistry Ph.D. Program, Florida International University, 11200 SW 8th Street, Miami, Florida 33199, USA
- Biomolecular Sciences Institute, School of Integrated Sciences and Humanity, Florida International University, 11200 SW 8th Street, Miami, Florida 33199, USA
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Regulation of mismatch repair by histone code and posttranslational modifications in eukaryotic cells. DNA Repair (Amst) 2015; 38:68-74. [PMID: 26719139 DOI: 10.1016/j.dnarep.2015.11.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 09/09/2015] [Accepted: 11/30/2015] [Indexed: 12/15/2022]
Abstract
DNA mismatch repair (MMR) protects genome integrity by correcting DNA replication-associated mispairs, modulating DNA damage-induced cell cycle checkpoints and regulating homeologous recombination. Loss of MMR function leads to cancer development. This review describes progress in understanding how MMR is carried out in the context of chromatin and how chromatin organization/compaction, epigenetic mechanisms and posttranslational modifications of MMR proteins influence and regulate MMR in eukaryotic cells.
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