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Korean Society for Biochemistry and Molecular Biology (생화학분자생물학회)
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Genetic disruption of ATAT1 causes RhoA downregulation through abnormal truncation of C/EBPβ

  • Jee-Hye Choi (Department of Life Science, Chung-Ang University) ;
  • Jangho Jeong (Department of Life Science, Chung-Ang University) ;
  • Jaegu Kim (Department of Life Science, Chung-Ang University) ;
  • Eunae You (Department of Life Science, Chung-Ang University) ;
  • Seula Keum (Department of Life Science, Chung-Ang University) ;
  • Seongeun Song (Department of Life Science, Chung-Ang University) ;
  • Ye Eun Hwang (Department of Life Science, Chung-Ang University) ;
  • Minjoo Ji (Department of Life Science, Chung-Ang University) ;
  • Kwon-Sik Park (Department of Microbiology, Immunology and Cancer Biology, University of Virginia) ;
  • Sangmyung Rhee (Department of Life Science, Chung-Ang University)
  • Received : 2023.12.01
  • Accepted : 2024.02.01
  • Published : 2024.06.30
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Abstract

Microtubule acetylation has been shown to regulate actin filament dynamics by modulating signaling pathways that control actin organization, although the precise mechanisms remain unknown. In this study, we found that the downregulation of microtubule acetylation via the disruption ATAT1 (which encodes α-tubulin N-acetyltransferase 1) inhibited the expression of RhoA, a small GTPase involved in regulating the organization of actin filaments and the formation of stress fibers. Analysis of RHOA promoter and chromatin immunoprecipitation assays revealed that C/EBPβ is a major regulator of RHOA expression. Interestingly, the majority of C/EBPβ in ATAT1 knockout (KO) cells was found in the nucleus as a 27-kDa fragment (referred to as C/EBPβp27) lacking the N-terminus of C/EBPβ. Overexpression of a gene encoding a C/EBPβp27-mimicking protein via an N-terminal deletion in C/EBPβ led to competitive binding with wild-type C/EBPβ at the C/EBPβ binding site in the RHOA promoter, resulting in a significant decrease of RHOA expression. We also found that cathepsin L (CTSL), which is overexpressed in ATAT1 KO cells, is responsible for C/EBPβp27 formation in the nucleus. Treatment with a CTSL inhibitor led to the restoration of RHOA expression by downregulation of C/EBPβp27 and the invasive ability of ATAT1 KO MDA-MB-231 breast cancer cells. Collectively, our findings suggest that the downregulation of microtubule acetylation associated with ATAT1 deficiency suppresses RHOA expression by forming C/EBPβp27 in the nucleus through CTSL. We propose that CTSL and C/EBPβp27 may represent a novel therapeutic target for breast cancer treatment.

Keywords

Acknowledgement

This research was supported by grants from the National Research Foundation of Korea (NRF), funded by the Korean government (MSIT) (No. RS-2023-00220089), the MOTIE (Ministry of Trade, Industry, and Energy) in Korea, under the Fostering Global Talents for Innovative Growth Program (P0017308) supervised by the Korea Institute for Advancement of Technology and the Chung-Ang University Research Scholarship Grants in 2022.

References

  1. Humphrey JD, Dufresne ER and Schwartz MA (2014) Mechanotransduction and extracellular matrix homeostasis. Nat Rev Mol Cell Biol 15, 802-812
  2. Seetharaman S and Etienne-Manneville S (2020) Cytoskeletal crosstalk in cell migration. Trends Cell Biol 30, 720-735
  3. Garcin C and Straube A (2019) Microtubules in cell migration. Essays Biochem 63, 509-520
  4. Inoue D, Obino D, Pineau J et al (2019) Actin filaments regulate microtubule growth at the centrosome. EMBO J 38, e99630
  5. Dubey T and Chinnathambi S (2021) Photodynamic sensitizers modulate cytoskeleton structural dynamics in neuronal cells. Cytoskeleton (Hoboken) 78, 232-248
  6. Fife CM, McCarroll JA and Kavallaris M (2014) Movers and shakers: cell cytoskeleton in cancer metastasis. Br J Pharmacol 171, 5507-5523
  7. O'Connor K and Chen M (2013) Dynamic functions of RhoA in tumor cell migration and invasion. Small GTPases 4, 141-147
  8. Chan CH, Lee SW, Li CF et al (2010) Deciphering the transcriptional complex critical for RhoA gene expression and cancer metastasis. Nat Cell Biol 12, 457-467
  9. Nomikou E, Stournaras C and Kardassis D (2017) Functional analysis of the promoters of the small GTPases RhoA and RhoB in embryonic stem cells. Biochem Biophys Res Commun 491, 754-759
  10. Bundy LM and Sealy L (2003) CCAAT/enhancer binding protein beta (C/EBPbeta)-2 transforms normal mammary epithelial cells and induces epithelial to mesenchymal transition in culture. Oncogene 22, 869-883
  11. Oh S, You E, Ko P, Jeong J, Keum S and Rhee S (2017) Genetic disruption of tubulin acetyltransferase, alphaTAT1, inhibits proliferation and invasion of colon cancer cells through decreases in Wnt1/beta-catenin signaling. Biochem Biophys Res Commun 482, 8-14
  12. Ko P, Choi JH, Song S et al (2021) Microtubule acetylation controls MDA-MB-231 breast cancer cell invasion through the modulation of endoplasmic reticulum stress. Int J Mol Sci 22, 6018
  13. Zahnow CA (2009) CCAAT/enhancer-binding protein beta: its role in breast cancer and associations with receptor tyrosine kinases. Expert Rev Mol Med 11, e12
  14. Park JS, Chu JS, Tsou AD et al (2011) The effect of matrix stiffness on the differentiation of mesenchymal stem cells in response to TGF-beta. Biomaterials 32, 3921-3930
  15. Williams SC, Baer M, Dillner AJ and Johnson PF (1995) CRP2 (C/EBP beta) contains a bipartite regulatory domain that controls transcriptional activation, DNA binding and cell specificity. EMBO J 14, 3170-3183
  16. Sudhan DR and Siemann DW (2015) Cathepsin L targeting in cancer treatment. Pharmacol Ther 155, 105-116
  17. Zhang W, Wang S, Wang Q, Yang Z, Pan Z and Li L (2014) Overexpression of cysteine cathepsin L is a marker of invasion and metastasis in ovarian cancer. Oncol Rep 31, 1334-1342
  18. Goulet B, Truscott M and Nepveu A (2006) A novel proteolytically processed CDP/Cux isoform of 90 kDa is generated by cathepsin L. Biol Chem 387, 1285-1293
  19. Reed NA, Cai D, Blasius TL et al (2006) Microtubule acetylation promotes kinesin-1 binding and transport. Curr Biol 16, 2166-2172