Belongs to the enolase family:2-phospho-D-glycerate = phosphoenolpyruvate + H2O.Involved in glycolytic pathway.
NCBI Summary:
This gene encodes alpha-enolase, one of three enolase isoenzymes found in mammals. Each isoenzyme is a homodimer composed of 2 alpha, 2 gamma, or 2 beta subunits, and functions as a glycolytic enzyme. Alpha-enolase in addition, functions as a structural lens protein (tau-crystallin) in the monomeric form. Alternative splicing of this gene results in a shorter isoform that has been shown to bind to the c-myc promoter and function as a tumor suppressor. Several pseudogenes have been identified, including one on the long arm of chromosome 1. Alpha-enolase has also been identified as an autoantigen in Hashimoto encephalopathy. [provided by RefSeq, Jan 2011]
General function
Metabolism, Enzyme
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Cellular localization
Cytoplasmic
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Ovarian function
Oogenesis, Oocyte maturation
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Effects of α-enolase Gene Silencing on Reproductive-related Hormone Receptor Expression and Steroid Hormone Synthesis of Primary Granulosa Cells from Goose F1 Follicles. Ji H et al. (2020) Enolases are enzymes in the glycolytic pathway, which catalyse the reversible conversion of D-2-phosphoglycerate into phosphoenol pyruvate in the second half of the pathway. In this research, the effects of α-enolase (ENO1) on steroid reproductive-related hormone receptor expression and on hormone synthesis of primary granulosa cells from goose F1 follicles were studied. Primary granulosa cells from the F1 follicles of eight healthy 8-month-old Zi geese were separated and cultured. An ENO1 interference expression vector was designed, constructed and transfected into primary cultured granulosa cells. The mRNA expression levels of follicle-stimulating hormone receptor (FSHR), luteinising hormone receptor (LHR), oestrogen receptor α (ER α), oestrogen receptor β (ER β), growth hormone receptor (GHR) and insulin-like growth factor binding protein-1 (IGFBP-1) in the cells were evaluated as were the secretion levels of oestradiol, activin, progesterone, testosterone, inhibin and follistatin in cell supernatant. α-enolase gene silencing reduced the expression of FSHR, LHR, ERα, ERβ, GHR, and IGFBP-1 mRNA, potentiated the secretion of oestrogen, progesterone, testosterone, and follistatin of granulosa cells, and hampered the production of activin and inhibin. ENO1 can regulate the reactivity of granulosa cells to reproductive hormones and regulate cell growth and development by adjusting their hormone secretion and reproductive hormone receptor expression. The study provided a better understanding of the functional action of ENO1 in the processes of goose ovary development and egg laying.//////////////////
Expression regulated by
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Ovarian localization
Oocyte, Cumulus, Granulosa
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Oocyte control of metabolic cooperativity between oocytes and companion granulosa cells: energy metabolism Sugiura K, et al 2005 .
Intercellular communication between oocytes and granulosa cells is essential for normal follicular differentiation and oocyte development. Subtraction hybridization was used to identify genes more highly expressed in cumulus cells than in mural granulosa cells of mouse antral follicles. This screen identified six genes involved in glycolysis: Eno1, Pkm2, Tpi, Aldoa, Ldh1, and Pfkp. When oocytes were microsurgically removed from cumulus cell-oocyte complexes, the isolated cumulus cells exhibited decreased expression levels of genes encoding glycolytic enzymes, glycolysis and activity of the tricarboxylic acid (TCA) cycle. These decreases were prevented by culturing the cumulus cells with paracrine factors secreted by fully grown oocytes. Paracrine factors from fully grown oocytes exhibited greater ability than those from growing oocytes to promote expression of genes encoding glycolytic enzymes and glycolysis in the granulosa cells of preantral follicles. However, neither fully grown nor growing oocytes secreted paracrine factors affecting activity of the TCA cycle. These results indicate that oocytes regulate glycolysis and the TCA cycle in granulosa cells in a manner specific to the population of granulosa cells and to the stage of growth and development of the oocyte. Oocytes control glycolysis in granulosa cells by regulating expression levels of genes encoding glycolytic enzymes. Therefore, mouse oocytes control the intercellular metabolic cooperativity between cumulus cells and oocytes needed for energy production by granulosa cells and required for oocyte and follicular development.
Follicle stages
Comment
Gonadotropins up-regulate the expression of enolase 2, but not enolase 1, in the rat ovary. Yoshioka N et al. It has been demonstrated that the glycolytic enzymes, enolase 1 (ENO1) and enolase 2 (ENO2), are expressed in the rat ovary. In the present study, we found that mRNA levels of ovarian ENO2 but not ENO1 in normal cycling adult female rats changed significantly during the estrous cycle: ovarian ENO2 mRNA levels at metestrus were lower than those at estrus. Single injection of human CG (hCG) or equine CG (eCG) into immature (3 week old) rats up-regulated ovarian expression of ENO2. hCG mainly increased ENO2 expression in oocytes and theca cells of preantral and antral follicles, and eCG did in theca cells of these follicles. In contrast, hCG and eCG did not affect the expression of ENO1, which was mainly expressed in granulosa cells. These results suggest that endogenous gonadotropins up-regulate expression of ENO2 in oocytes and theca cells of preantral and antral follicles, which would activate glycolysis in these cells. It is also suggested that the activated glycolysis is necessary for ovarian functions such as follicle growth and maturation, and hormone production.