# Comparative Proteomics of Two Flor Yeasts in Sparkling Wine Fermentation: First Approach
## 4 Discussion
UTH1 can reduce the concentration of some mitochondrial proteins, so it may have the ability to regulate mitochondrial function. It also appears that it may affect the function of the yeast cell wall [53]. NCA3 and UTH1 belong to the same family of SUN proteins, and these proteins participate in mitochondrial biogenesis, autophagy, cytokinesis, cell wall structure, and DNA replication [53]. These proteins are involved in reforming the cell wall during the transition from the exponential to stationary phase [54]. In strain N62, a protein with significant differences related to the cell wall was identified, QRI1, which synthesizes the chitin found in the cell wall [55]. This protein was quantified at a higher level because YPG1 was expressed at a lower level in this strain according to [PERSON] et al. [41]. In strain G1, two proteins related to endocytosis have been quantified with significant differences. EDE1 and CLC1 are the first proteins to reach endocytic sites [56]. Furthermore, they are important for good dynamics in endocytic proteins, which arrive afterwards and for cargo adsorption [57]. Most ergosterol in fungi is located in the plasma membrane [58], as well as in the vacuole membranes [59]. This sterol is important for good endocytic apparatus execution [60]. This could explain why ERG8, which is part of ergosterol biosynthesis [61], presents significant differences in this strain. In the N62 strain, the PIL1 protein could inhibit protein kinases that participate in signaling pathways for cell wall integrity [62] and participate in endocytosis [63]. The specific proteins of this strain identified SEC18, which is necessary for vesicle-mediated transport [64], EIS1, to form eisosomes [65], which can respond to different types of stress [66], and LSP1. This, together with PIL1, is an essential protein in the formation of eisosomes, thus allowing for the endocytosis process [60]. It has been discovered that PIL1 is also found in the outer membrane of mitochondria, and in its absence, mitophagy occurs [67]; this could explain the differences in quantification between strains, since in G1 this protein has been identified in a lower proportion, and this might indicate that mitophagy has begun and initiates the autophagy process. G1 reached 3 bars of pressure at 52 days and the N62 strain at 27 days. These results could explain why in G1 proteases have been identified with significant differences related to their degradation in the vacuoles, signs that indicate the beginning of autophagy, such as proteins PRC1, PRB1, ATG42/YBR139W, and proteasome-related proteins, PRE8, PRE9, and PUP2, which also participate in autophagy [68; 69]. Finally, in the N62 strain, a greater number of proteins were obtained with significant differences and specificities related to ribosomes and the transcription and translation of proteins [70]. The protein involved in transcription in this strain was TEF2, and specifically, the following: RSC6, SPT5, NCL1, and ARP5. Those in translation were the following: PAB1, GCD11, MAP1, and GIS2. Specifically, SUP35, PRT1, SUI3, SUP45, RPG1, DED81, FUN12, TPA1, and MKT1 were found in protein synthesis or part of the ribosome, as well as RPL25, RPS20, RPS15, SSZ1, and RPS14B; proteins from part of the mitochondrial ribosome include MRPL3 and, specifically, RPL28, RPL7A, RPL33A, RPL22A, RPS13, RPL27A, RPL31A, RPL20B, RPS24A, RPS6B, RPL23A, RPS11B, RPL4A, RPS17B, RPL16B, NHP2, MRT4, RPS1A, RPL14B, RPL34B, RPL10, RPS10B, RPL4B, RPL21A, EMG1, FAL1, RPS22B, ZUO1, and NOP2. Also specifically associated with mitochondrial ribosomes were the following: MRP20, MRPS5, MRPL7, MRPL40, MRPS9, MRPL49, MRPS18, RSM26, YML6, MRPS12, RSM23, MRPS8, MRLP1, MRPL51, and MRPL35. Those related to mRNA were as follows: NPL3 and PUB1. Specifically, this involved NAM7, PRP19, NAB3, PUF6, PUS7, and PUS1. All of this is closely associated with the high rate of cell growth and viability observed in this strain.