Characterization of the novel protein transmembrane and coiled-coil domain family 1 (TMCC1)

Saccharomyces cerevisiae exhibits polarized growth during two phases of its life cycle, budding and mating. The site for polarization during vegetative growth is determined genetically: a and alpha haploid cells exhibit an axial budding pattern, and a/alpha diploid cells exhibit a bipolar pattern. During mating, each cell polarizes towards its partner to ensure efficient mating. SPA2 is required for the bipolar budding pattern (Snyder. M 1989. J. Cell Biol. 108:1419-1429; Zahner, J.A., H.A. Harkins, and J.R. Pringle. 1996. Mol. Cell. Biol. 16:1857-1870) and polarization during mating (Snyder, M., S. Gehrung, and B.D. Page. 1991. J. Cell Biol. 114: 515-532). We previously identified mutants defective in PEA2 and SPA2 which alter cell polarization in the presence of mating pheromone in a similar manner (Chenevert, J., N. Valtz, and I. Herskowitz. 1994. Genetics, 136:1287-1297). Here we report the further characterization of these mutants. We have found that PEA2 is also required for the bipolar budding pattern and that it encodes a novel protein with a predicted coiled-coil domain. Pea2p is expressed in all cell types and is localized to sites of polarized growth in budding and mating cells in a pattern similar to Spa2p, Pea2p and Spa2p exhibit interdependent localization: Spa2p is produced in pea2 mutants but fails to localize properly; Pea2p is not stably produced in spa2 mutants. These results suggest that Pea2p and Spa2p function together as a complex to generate the bipolar budding pattern and to guarantee proper polarization during mating.

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TMCC3 localizes at the three-way junctions for the proper tubular network of the endoplasmic reticulum

Biochemical Journal ◽

10.1042/bcj20190359 ◽

2019 ◽

Vol 476 (21) ◽

pp. 3241-3260

Author(s):

Sindhu Wisesa ◽

Yasunori Yamamoto ◽

Toshiaki Sakisaka

Keyword(s):

Endoplasmic Reticulum ◽

Membrane Proteins ◽

Membrane Protein ◽

Mammalian Cells ◽

Coiled Coil ◽

Transmembrane Domains ◽

Domain Family ◽

Coiled Coil Domain ◽

U2os Cells ◽

Er Membrane

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. In this study, we report 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. 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 in U2OS cells. The TMCC3 knockdown phenotype was partially rescued by the overexpression of atlastin-2, suggesting that TMCC3 knockdown would decrease the activity of atlastins. These results indicate that TMCC3 localizes at the three-way junctions for the proper tubular ER network.

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Roles of the novel coiled-coil protein Rng10 in septum formation during fission yeast cytokinesis

Molecular Biology of the Cell ◽

10.1091/mbc.e16-03-0156 ◽

2016 ◽

Vol 27 (16) ◽

pp. 2528-2541 ◽

Cited By ~ 6

Author(s):

Yajun Liu ◽

I-Ju Lee ◽

Mingzhai Sun ◽

Casey A. Lower ◽

Kurt W. Runge ◽

...

Keyword(s):

Fission Yeast ◽

Rho Gtpases ◽

Cellular Localization ◽

Affinity Purification ◽

Coiled Coil ◽

The Novel ◽

Septum Formation ◽

Division Site ◽

And Function

Rho GAPs are important regulators of Rho GTPases, which are involved in various steps of cytokinesis and other processes. However, regulation of Rho-GAP cellular localization and function is not fully understood. Here we report the characterization of a novel coiled-coil protein Rng10 and its relationship with the Rho-GAP Rga7 in fission yeast. Both rng10Δ and rga7Δ result in defective septum and cell lysis during cytokinesis. Rng10 and Rga7 colocalize on the plasma membrane at the cell tips during interphase and at the division site during cell division. Rng10 physically interacts with Rga7 in affinity purification and coimmunoprecipitation. Of interest, Rga7 localization is nearly abolished without Rng10. Moreover, Rng10 and Rga7 work together to regulate the accumulation and dynamics of glucan synthases for successful septum formation in cytokinesis. Our results show that cellular localization and function of the Rho-GAP Rga7 are regulated by a novel protein, Rng10, during cytokinesis in fission yeast.

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Characterization of the baculovirus Choristoneura fumiferana multicapsid nuclear polyhedrosis virus p10 gene indicates that the polypeptide contains a coiled-coil domain

Journal of General Virology ◽

10.1099/0022-1317-76-12-2923 ◽

1995 ◽

Vol 76 (12) ◽

pp. 2923-2932 ◽

Cited By ~ 18

Author(s):

J. A. Wilson ◽

J. E. Hill ◽

J. Kuzio ◽

P. Faulkner

Keyword(s):

Nuclear Polyhedrosis Virus ◽

Choristoneura Fumiferana ◽

Coiled Coil ◽

Coiled Coil Domain ◽

Polyhedrosis Virus ◽

Nuclear Polyhedrosis

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Fa1p is a 171 kDa protein essential for axonemal microtubule severing in Chlamydomonas

Journal of Cell Science ◽

10.1242/jcs.113.11.1963 ◽

2000 ◽

Vol 113 (11) ◽

pp. 1963-1971 ◽

Cited By ~ 3

Author(s):

R.J. Finst ◽

P.J. Kim ◽

E.R. Griffis ◽

L.M. Quarmby

Keyword(s):

Coiled Coil ◽

Subcellular Fractionation ◽

Rt Pcr ◽

Type Locus ◽

Microtubule Severing ◽

Calmodulin Binding ◽

Amino Terminal ◽

Binding Domains ◽

Coiled Coil Domain ◽

Novel Protein

A key event in deflagellation or deciliation is the severing of the nine outer-doublet axonemal microtubules at a specific site in the flagellar transition zone. Previous genetic analysis revealed three genes that are essential for deflagellation in Chlamydomonas. We have now identified the first of these products, Fa1p, a protein required for Ca(2+)-dependent, axonemal microtubule severing. Genetic mapping and the availability of a tagged allele allowed us to physically map the gene to the centromere-proximal domain of the mating-type locus. We identified clones of Chlamydomonas genomic DNA that rescued the Ca(2+)-dependent axonemal microtubule severing defect of fa1 mutants. The FA1 cDNA, obtained by RT-PCR, encodes a novel protein of 171 kDa, which is predicted to contain an amino-terminal coiled-coil domain and three Ca(2+)/calmodulin binding domains. By western analysis and subcellular fractionation, the FA1 product is enriched in flagellar-basal body complexes. Based on these observations and previous studies, we hypothesize that a Ca(2+)-activated, Ca(2+)-binding protein binds Fa1p leading ultimately to the activation of axonemal microtubule severing.

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