In MAP1S-deficient macrophages, phagocytosis of bacteria is impaired, and MAP1S directly interacts with MyD88 affecting the TLR signaling pathway, indicating its role in innate immune defense [1]. In mice, deletion of MAP1S leads to an accumulation of fibrosis-related proteins and development of renal fibrosis in aged mice, suggesting its importance in preventing renal fibrosis [4]. In a murine model of hepatocarcinoma, elevation of MAP1S enhances autophagy to suppress genome instability and tumorigenesis [2]. Also, knockdown of MAP1S in HCCLM3 cells suppresses their growth in vitro and in vivo, and in breast cancer cells, knockdown almost completely abrogates the tumor-suppressing effect of flagellin treatment [5].

In conclusion, MAP1S plays essential roles in cell division, autophagy, innate immune response, and fibrosis prevention. Studies using gene-knockout models in mice have revealed its significance in disease areas such as renal fibrosis, hepatocarcinoma, and breast cancer. These findings help in understanding the biological functions of MAP1S and provide potential targets for disease treatment [1-5].

References:

1. Shi, Ming, Zhang, Yifan, Liu, Leyuan, Li, Yu, Zhang, Dekai. 2015. MAP1S Protein Regulates the Phagocytosis of Bacteria and Toll-like Receptor (TLR) Signaling. In The Journal of biological chemistry, 291, 1243-50. doi:10.1074/jbc.M115.687376. https://pubmed.ncbi.nlm.nih.gov/26565030/

2. Liu, Leyuan, McKeehan, Wallace L, Wang, Fen, Xie, Rui. 2012. MAP1S enhances autophagy to suppress tumorigenesis. In Autophagy, 8, 278-80. doi:10.4161/auto.8.2.18939. https://pubmed.ncbi.nlm.nih.gov/22301994/

3. Guan, Yuanyue, Li, Jiaxi, Sun, Bin, Chen, Dexi, Wang, Yanjun. 2024. HBx-induced upregulation of MAP1S drives hepatocellular carcinoma proliferation and migration via MAP1S/Smad/TGF-β1 loop. In International journal of biological macromolecules, 281, 136327. doi:10.1016/j.ijbiomac.2024.136327. https://pubmed.ncbi.nlm.nih.gov/39374711/

4. Xu, Guibin, Yue, Fei, Huang, Hai, Chen, Qi, Liu, Leyuan. . Defects in MAP1S-mediated autophagy turnover of fibronectin cause renal fibrosis. In Aging, 8, 977-85. doi:10.18632/aging.100957. https://pubmed.ncbi.nlm.nih.gov/27236336/

5. Shi, Ming, Yao, Yuanfei, Han, Fang, Li, Yiqun, Li, Yu. 2014. MAP1S controls breast cancer cell TLR5 signaling pathway and promotes TLR5 signaling-based tumor suppression. In PloS one, 9, e86839. doi:10.1371/journal.pone.0086839. https://pubmed.ncbi.nlm.nih.gov/24466264/