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9.B.390.  The ER Tubular Junction (ER-TJ) Family 

The tubular network of the endoplasmic reticulum (ER) is formed by connecting ER tubules through three-way junctions. Two classes of the conserved ER membrane proteins, atlastins and lunapark, have been shown to reside at the three-way junctions so far and be involved in the generation and stabilization of the three-way junctions. Wisesa et al. 2019 reported TMCC3 (transmembrane and coiled-coil domain family 3), a member of the TEX28 family, as another ER membrane protein that resides at the three-way junctions in mammalian cells. When the TEX28 family members were transfected into U2OS cells, TMCC3 specifically localized at the three-way junctions in the peripheral ER. TMCC3 bound to atlastins through the C-terminal transmembrane domains of TMCC3. A TMCC3 mutant lacking the N-terminal coiled-coil domain abolished localization to the three-way junctions, suggesting that TMCC3 localized independently of binding to atlastins. TMCC3 knockdown caused a decrease in the number of three-way junctions and expansion of ER sheets, leading to a reduction of the tubular ER network. The TMCC3 knockdown phenotype was partially rescued by the overexpression of atlastin-2, suggesting that TMCC3 knockdown would decrease the activity of atlastins. Thus, TMCC3 localizes at the three-way junctions for the proper tubular ER network (Wisesa et al. 2019).

References associated with 9.B.390 family:

Bowling, S.A., J.D. Clarke, Y. Liu, D.F. Klessig, and X. Dong. (1997). The cpr5 mutant of Arabidopsis expresses both NPR1-dependent and NPR1-independent resistance. Plant Cell 9: 1573-1584. 9338960
Breuss, M.W., A. Nguyen, Q. Song, T. Nguyen, V. Stanley, K.N. James, D. Musaev, G. Chai, S.A. Wirth, P. Anzenberg, R.D. George, A. Johansen, S. Ali, M. Zia-Ur-Rehman, T. Sultan, M.S. Zaki, and J.G. Gleeson. (2018). Mutations in LNPK, Encoding the Endoplasmic Reticulum Junction Stabilizer Lunapark, Cause a Recessive Neurodevelopmental Syndrome. Am J Hum Genet 103: 296-304. 30032983
Chen, S., T. Desai, J.A. McNew, P. Gerard, P.J. Novick, and S. Ferro-Novick. (2015). Lunapark stabilizes nascent three-way junctions in the endoplasmic reticulum. Proc. Natl. Acad. Sci. USA 112: 418-423. 25548161
Faisal, M.B., T.S. Gechev, B. Mueller-Roeber, and P.P. Dijkwel. (2020). Putative alternative translation start site-encoding nucleotides of CPR5 regulate growth and resistance. BMC Plant Biol 20: 295. 32600419
Hu, J., Y. Shibata, P.P. Zhu, C. Voss, N. Rismanchi, W.A. Prinz, T.A. Rapoport, and C. Blackstone. (2009). A class of dynamin-like GTPases involved in the generation of the tubular ER network. Cell 138: 549-561. 19665976
Kirik, V., D. Bouyer, U. Schöbinger, N. Bechtold, M. Herzog, J.M. Bonneville, and M. Hülskamp. (2001). CPR5 is involved in cell proliferation and cell death control and encodes a novel transmembrane protein. Curr. Biol. 11: 1891-1895. 11728314
Moriya, K., K. Nagatoshi, Y. Noriyasu, T. Okamura, E. Takamitsu, T. Suzuki, and T. Utsumi. (2013). Protein N-myristoylation plays a critical role in the endoplasmic reticulum morphological change induced by overexpression of protein Lunapark, an integral membrane protein of the endoplasmic reticulum. PLoS One 8: e78235. 24223779
Perazza, D., F. Laporte, C. Balagué, F. Chevalier, S. Remo, M. Bourge, J. Larkin, M. Herzog, and G. Vachon. (2011). GeBP/GPL transcription factors regulate a subset of CPR5-dependent processes. Plant Physiol. 157: 1232-1242. 21875893
Shemesh, T., R.W. Klemm, F.B. Romano, S. Wang, J. Vaughan, X. Zhuang, H. Tukachinsky, M.M. Kozlov, and T.A. Rapoport. (2014). A model for the generation and interconversion of ER morphologies. Proc. Natl. Acad. Sci. USA 111: E5243-5251. 25404289
Wang, S., H. Tukachinsky, F.B. Romano, and T.A. Rapoport. (2016). Cooperation of the ER-shaping proteins atlastin, lunapark, and reticulons to generate a tubular membrane network. Elife 5:. 27619977
Wang, S., Y. Gu, S.G. Zebell, L.K. Anderson, W. Wang, R. Mohan, and X. Dong. (2014). A noncanonical role for the CKI-RB-E2F cell-cycle signaling pathway in plant effector-triggered immunity. Cell Host Microbe 16: 787-794. 25455564
Wisesa, S., Y. Yamamoto, and T. Sakisaka. (2019). TMCC3 localizes at the three-way junctions for the proper tubular network of the endoplasmic reticulum. Biochem. J. 476: 3241-3260. 31696206
Yang, Y. and D.J. Klionsky. (2020). A novel reticulophagy receptor, Epr1: a bridge between the phagophore protein Atg8 and ER transmembrane VAP proteins. Autophagy 1-2. [Epub: Ahead of Print] 33121335
Yoshida, S., M. Ito, I. Nishida, and A. Watanabe. (2002). Identification of a novel gene HYS1/CPR5 that has a repressive role in the induction of leaf senescence and pathogen-defence responses in Arabidopsis thaliana. Plant J. 29: 427-437. 11846876