9.B.45. The Fungal Mating-type Pheromone Receptor (MAT-PR) Family The MAT-PR family consists of proteins with 7 TMSs and is considered to comprise Class D GPCR receptors (Shalaeva et al. 2015). The G protein-coupled receptors Ste2 and Ste3 bind α- and a-factor, respectively, in Saccharomyces cerevisiae. These receptors share a similar conformation, with seven transmembrane segments, three intracellular loops, a C-terminal tail, and three extracellular loops. However, the amino acid sequences of these two receptors bear little resemblance to each other, and the two ligands, α-factor and a-factor, have different sequences although both receptors activate the same G protein (Gastaldi et al. 2016). These two subfamilies within the MMAT-PR Family are very distantly related, but both are distantly related to other GPCRs in TC Family 9.A.14. They are therefore members of the TOG superfamily (Yee et al. 2013).
References:
Di Segni, G., S. Gastaldi, M. Zamboni, and G.P. Tocchini-Valentini. (2011). Yeast pheromone receptor genes STE2 and STE3 are differently regulated at the transcription and polyadenylation level. Proc. Natl. Acad. Sci. USA 108: 17082-17086.
Gastaldi, S., M. Zamboni, G. Bolasco, G. Di Segni, and G.P. Tocchini-Valentini. (2016). Analysis of random PCR-originated mutants of the yeast Ste2 and Ste3 receptors. Microbiologyopen 5: 670-686.
Krystofova, S. and K.A. Borkovich. (2006). The predicted G-protein-coupled receptor GPR-1 is required for female sexual development in the multicellular fungus Neurospora crassa. Eukaryot. Cell. 5: 1503-1516.
Nakayama, N., A. Miyajima, and K. Arai. (1987). Common signal transduction system shared by STE2 and STE3 in haploid cells of Saccharomyces cerevisiae: autocrine cell-cycle arrest results from forced expression of STE2. EMBO. J. 6: 249-254.
Shalaeva, D.N., M.Y. Galperin, and A.Y. Mulkidjanian. (2015). Eukaryotic G protein-coupled receptors as descendants of prokaryotic sodium-translocating rhodopsins. Biol Direct 10: 63.
Turrà, D., M. El Ghalid, F. Rossi, and A. Di Pietro. (2015). Fungal pathogen uses sex pheromone receptor for chemotropic sensing of host plant signals. Nature 527: 521-524.
Vitale, S., A. Partida-Hanon, S. Serrano, &.#.1.9.3.;. Martínez-Del-Pozo, A. Di Pietro, D. Turrà, and M. Bruix. (2017). Structure-Activity Relationship of α Mating Pheromone from the Fungal Pathogen Fusarium oxysporum. J. Biol. Chem. 292: 3591-3602.
Yee, D.C., M.A. Shlykov, A. Västermark, V.S. Reddy, S. Arora, E.I. Sun, and M.H. Saier, Jr. (2013). The transporter-opsin-G protein-coupled receptor (TOG) superfamily. FEBS J. 280: 5780-5800.
Examples:
TC#	Name	Organismal Type	Example
9.B.45.1.1	Mating-type pheromone α-receptor of 431 aas and 7 TMSs, STE2 (Nakayama et al. 1987). The G protein-coupled receptors Ste2 and Ste3 bind α- and a-factor, respectively, in Saccharomyces cerevisiae. These receptors share a similar conformation, with seven transmembrane segments, three intracellular loops, a C-terminal tail, and three extracellular loops. However, the amino acid sequences of these two receptors bear little resemblance to each other, and the two ligands, α-factor and a-factor, have different sequences although both receptors activate the same G protein (Gastaldi et al. 2016).		α-receptor of Saccharomyces cerevisiae

9.B.45.1.2	*α-factor receptor of 380 aas and 7 TMSs, STE2 (Vitale et al.* 2017).**		α-receptor of Fusarium oxysporum

9.B.45.1.3	*α-factor receptor of 566 aas and 7 TMSs, STE2 (Turrà et al.* 2015).**		α-factor of Neurospora crassa

9.B.45.1.4	Uncharacterized protein of 423 aas and 7 TMSs.		UP of Cladophialophora carrionii

9.B.45.1.5	Uncharacterized protein of 361 aas and 7 TMSs		*UP of Gloeophyllum trabeum* (Brown rot fungus)**

Examples:
TC#	Name	Organismal Type	Example
9.B.45.2.1	*a-factor receptor of 470 aas and 7 TMSs, STE3 (Di Segni et al.* 2011)**		a-factor receptor of Saccharomyces cerevisiae

9.B.45.2.2	*a-factor receptor of 543 aas and 7 TMSs, STE3 (Turrà et al.* 2015).**		a-factor receptor of Fusarium oxysporum

9.B.45.2.3	a-factor receptor of 724 aas and 7 TMSs, STE3 (Krystofova and Borkovich 2006).		a-factor receptor of Neurospora crassa

9.B.45.2.4	Pheromone receptor of 398 aas and 7 TMSs		Pheromone receptor of Lentinula edodes (Shiitake mushroom) (Lentinus edodes)

9.B.45.2.5	Ste-3-like pheromone receptor 4, Ste3.4 of 601 aas and 7 TMSs		Ste3.4 of Volvariella volvacea