MORN2, short for membrane occupation and recognition nexus-motif protein 2, is a protein-coding gene. The MORN motif it contains is reported to regulate bioelectrical signal homeostasis in cardiomyocytes. MORN2 is involved in multiple biological processes, including LC3-associated phagocytosis, which is a non-canonical autophagy process regulating phagosome maturation in macrophages, and it may also be associated with the virulence of Fusobacterium nucleatum in colorectal cancer [2,3,4,5,6,7,8].

In a study using Morn2-/-mice generated by Nuclease technology [1], the knockout mice were infertile, and their sperm showed severe motility defects, abnormal morphology (bent heads, aberrant mitochondrial sheath formation), lower mitochondrial membrane potential, higher levels of reactive oxygen species, and decreased mitochondrial respiratory activity. This indicates that MORN2 is essential for male fertility and functions in mitochondrial sheath formation and regulation of mitochondrial respiratory activity.

In summary, MORN2 is crucial for male fertility as demonstrated by the Morn2-/-mouse model. It also plays important roles in LC3-associated phagocytosis and potentially in the pathogenesis related to Fusobacterium nucleatum. Research on MORN2 helps us understand biological processes such as spermatogenesis, autophagy, and bacterial-host interactions, providing insights into related diseases like male infertility and colorectal cancer [1,2,3,4,5,6,7,8].

References:

1. Liu, Yining, Li, Tongtong, Shi, Mingze, Zhang, Haobo, Huang, Tao. 2024. MORN2 regulates the morphology and energy metabolism of mitochondria and is required for male fertility in mice. In Journal of translational medicine, 22, 240. doi:10.1186/s12967-024-05010-3. https://pubmed.ncbi.nlm.nih.gov/38443933/

2. Morita, Maya, Kajiye, Mayu, Sakurai, Chiye, Hori, Naohiro, Hatsuzawa, Kiyotaka. 2020. Characterization of MORN2 stability and regulatory function in LC3-associated phagocytosis in macrophages. In Biology open, 9, . doi:10.1242/bio.051029. https://pubmed.ncbi.nlm.nih.gov/32414768/

3. Abnave, Prasad, Mottola, Giovanna, Gimenez, Gregory, Mege, Jean-Louis, Ghigo, Eric. . Screening in planarians identifies MORN2 as a key component in LC3-associated phagocytosis and resistance to bacterial infection. In Cell host & microbe, 16, 338-50. doi:10.1016/j.chom.2014.08.002. https://pubmed.ncbi.nlm.nih.gov/25211076/

4. Ranjbar, Maryam, Salehi, Rasoul, Haghjooy Javanmard, Shaghayegh, Manian, Mostafa, Nedaeinia, Reza. 2021. The dysbiosis signature of Fusobacterium nucleatum in colorectal cancer-cause or consequences? A systematic review. In Cancer cell international, 21, 194. doi:10.1186/s12935-021-01886-z. https://pubmed.ncbi.nlm.nih.gov/33823861/

5. Zhang, Xuqiang, Wang, Yuxin, Fan, Ruochen, Liu, Baoquan, Quan, Chunshan. 2023. Quantitative Proteomic Analysis of Outer Membrane Vesicles from Fusobacterium nucleatum Cultivated in the Mimic Cancer Environment. In Microbiology spectrum, 11, e0039423. doi:10.1128/spectrum.00394-23. https://pubmed.ncbi.nlm.nih.gov/37341631/

6. Manson McGuire, Abigail, Cochrane, Kyla, Griggs, Allison D, Allen-Vercoe, Emma, Earl, Ashlee M. 2014. Evolution of invasion in a diverse set of Fusobacterium species. In mBio, 5, e01864. doi:10.1128/mBio.01864-14. https://pubmed.ncbi.nlm.nih.gov/25370491/

7. Umaña, Ariana, Sanders, Blake E, Yoo, Christopher C, Verbridge, Scott S, Slade, Daniel J. 2019. Utilizing Whole Fusobacterium Genomes To Identify, Correct, and Characterize Potential Virulence Protein Families. In Journal of bacteriology, 201, . doi:10.1128/JB.00273-19. https://pubmed.ncbi.nlm.nih.gov/31501282/

8. Liu, Jinjing, Hsieh, Ching-Lin, Gelincik, Ozkan, Lipkin, Steven M, Chang, Yung-Fu. 2019. Proteomic characterization of outer membrane vesicles from gut mucosa-derived fusobacterium nucleatum. In Journal of proteomics, 195, 125-137. doi:10.1016/j.jprot.2018.12.029. https://pubmed.ncbi.nlm.nih.gov/30634002/