Glyceraldehyde-3-phosphate dehydrogenase, spermatogenic (GAPDHS)

Glyceraldehyde-3-phosphate dehydrogenase, spermatogenic (GAPDHS), is a testis-specific isozyme of glyceraldehyde-3-phosphate dehydrogenase that catalyzes a key step in glycolysis: conversion of glyceraldehyde 3-phosphate to 1,3-diphosphoglycerate in a NAD-dependent reaction. Unlike the ubiquitous somatic GAPDH, GAPDHS is expressed exclusively during spermatogenesis and is tightly associated with the cytoskeletal fibrous sheath of the sperm flagellum via a distinctive N-terminal proline-rich domain[1][3][4][6]. This localization facilitates compartmentalized ATP generation in the sperm tail, where mitochondrial ATP diffusion is limited[4][5]. Genetic deletion or pharmacological inhibition of GAPDHS in animal models results in severely impaired sperm motility and absolute male infertility without affecting other aspects of spermatogenesis[3][5]. These properties make GAPDHS a compelling and highly specific therapeutic target for male contraception and for assessing environmental risks to male fertility. There is emerging evidence of roles in cancer biology and metastasis[7]. Note: GAPDHS, GAPD2, and GAPDS all refer to the same protein in humans; the most scientifically recognized name is "Glyceraldehyde-3-phosphate dehydrogenase, spermatogenic" (abbreviation: GAPDHS)[1][6].

Other names

Glyceraldehyde-3-phosphate dehydrogenase, testis-specificGAPDHSGAPD2GAPDH2GAPDSGAPDH-2HSD-35HEL-S-278Spermatogenic cell-specific glyceraldehyde 3-phosphate dehydrogenase 2Spermatogenic glyceraldehyde-3-phosphate dehydrogenaseEpididymis secretory protein Li 278

Inhibition of GAPDHS blocks glycolytic ATP production in sperm, leading to impaired sperm motility and infertility (potential male contraceptive strategy)