Table 5 Proteins associated with fertility related functions obtained from UniProt database and STRAP annotation tool
From: Major protein alterations in spermatozoa from infertile men with unilateral varicocele
Uniprot No. | Gene name | Protein name | Expression | Function | References |
|---|---|---|---|---|---|
O75952 | CABYR | Calcium-binding tyrosine phosphorylation-regulated protein isoform c | ↓ | May function as a regulator of both motility- and head-associated functions such as capacitation and the acrosome reaction. | [39] |
O75969 | AKAP3 | A-kinase anchor protein 3 | ↓ | May function as a regulator of both motility- and head-associated functions such as capacitation and the acrosome reaction. | |
P02647 | APOA1 | Apolipoprotein A-I preproprotein | ↓ | Activates spermatozoa motility. | |
P04279 | SEMG1 | Semenogelin-1 preproprotein | ↓ | Constitutes major gel forming proteins in human semen. | |
P09622 | DLD | Dihydrolipoyl dehydrogenase, mitochondrial precursor | ↑ | Lipoamide dehydrogenase is a component of the glycine cleavage system as well as of the alpha-ketoacid dehydrogenase complexes. Involved in the hyperactivation of spermatazoa during capacitation and in the spermatazoa acrosome reaction. | |
P0C8F1 | PATE4 | Prostate and testis expressed protein 4 | Fertile group only | May modulate the function of nicotinic acetylcholine receptors. May enhance sperm motility. | [51] |
P10323 | ACR | Acrosin precursor | ↓ | Acrosin is the major protease of mammalian spermatozoa. It is a serine protease of trypsin-like cleavage specificity; proacrosin and stored in the acrosome. | |
P16562 | CRISP2 | Cysteine-rich secretory protein 2 precursor | Unilateral varicocele group only | May regulate some ion channels’ activity and thereby regulate calcium fluxes during sperm capacitation. | |
P21266 | GSTM3 | Glutathione S-transferase Mu 3 | ↑ | Conjugation of reduced glutathione to a wide number of exogenous and endogenous hydrophobic electrophiles. May govern uptake and detoxification of both endogenous compounds and xenobiotics at the testis and brain blood barriers. | |
P49221 | TGM4 | Protein-glutamine gamma-glutamyltransferase 4 | ↑ | Associated with the mammalian reproductive process. Catalyzes the cross-linking of proteins and the conjugation of polyamines to specific proteins in the seminal tract. | [46] |
P56597 | NME5 | Nucleoside diphosphate kinase homolog 5 | Fertile group only | Does not seem to have NDK kinase activity. Confers protection from cell death by Bax and alters the cellular levels of several antioxidant enzymes including Gpx5. May play a role in spermiogenesis by increasing the ability of late-stage spermatids to eliminate reactive oxygen species. | [61] |
P61916 | NPC2 | Epididymal secretory protein E1 precursor | ↑ | Plays important role in exit of cholesterol from endosomal/ lysosomal compartment. | |
P78540 | ARG2 | Arginase-2, mitochondrial precursor | Unilateral varicocele group only | Arginase activity negatively associated to sperm concentration and positively with sperm motility. | |
Q13733 | ATP1A4 | Sodium/potassium-transporting ATPase subunit alpha-4 isoform 1 | ↓ | Essential for germ cell gene expression; sperm with deficiency show bent in the tail, abnormal ion regulation and reduced motility. | [67] |
Q15506 | SPA17 | Sperm surface protein Sp17 | ↓ | Sperm surface zona pellucida binding protein. Helps to bind spermatozoa to the zona pellucida with high affinity. Might function in binding zona pellucida and carbohydrates. | |
Q5BJF6 | ODF2 | Outer dense fiber protein 2 isoform 3 | ↑ | Seems to be a major component of sperm tail outer dense fibers (ODF). ODFs are filamentous structures located on the outside of the axoneme in the midpiece and principal piece of the mammalian sperm tail and may help to maintain the passive elastic structures and elastic recoil of the sperm tail. May have a modulating influence on sperm motility. Functions as a general scaffold protein that is specifically localized at the distal/ sub distal appendages of mother centrioles. Component of the centrosome matrix required for the localization of PLK1 and NIN to the centrosomes. Required for the formation and/or maintenance of normal CETN1 assembly. | |
Q8IZP9 | GPR64 | G-protein coupled receptor 64 isoform 2 precursor | ↑ | Could be involved in a signal transduction pathway controlling epididymal function and male fertility. | |
Q8NCR6 | SMRP1 | Spermatid-specific manchette-related protein | Fertile group only | May play a role in spermatogenesis. May be involved in nuclear shaping during spermiogenesis and transport of proteins. | [76] |
Q8TAA3 | PSMA8 | Proteasome subunit alpha type-7-like isoform 2 | ↑ | Component of the spermatozoa proteasome. | |
Q8TC29 | ENKUR | Enkurin | ↓ | Adapter that functions to localize calcium-sensitive signal transduction machinery in sperm to a calcium-permeable ion channel. | [81] |
Q8WWU5 | TCP11 | T-complex protein 11 homolog isoform 1 | Fertile group only | May play an important role in sperm function and fertility. | |
Q8WYR4 | RSPH1 | Radial spoke head 1 homolog | ↓ | May play an important role in male meiosis. | |
Q96A08 | HIST1H2BA | Histone H2B type 1-A | ↑ | Variant histone specifically required to direct the transformation of dissociating nucleosomes to protamine in male germ cells. Entirely replaces classical histone H2B prior nucleosome to protamine transition and probably acts as a nucleosome dissociating factor that creates a more dynamic chromatin facilitating the large-scale exchange of histones. Also expressed maternally and is present in the female pronucleus. | [86] |
Q96PU9 | ODF3 | Outer dense fiber protein 3 | Fertile group only | Outer dense fibers are filamentous structures located on the outside of the axoneme in the midpiece and principal piece of the mammalian sperm tail. May help to maintain the passive elastic structures and elastic recoil of the sperm tail. | |
Q96QH8 | SPACA5 | Sperm acrosome-associated protein 5 precursor | Fertile group only | Sperm acrosome-associated protein 5. | [88] |
Q99497 | PARK7 | Protein DJ-1 | ↑ | It acts as atypical peroxiredoxin –like peroxidase that scavenges hydrogen peroxide. | |
Q9H1X1 | RSPH9 | Radial spoke head protein 9 homolog isoform 1 | ↓ | Sperm and flagella axonemes. They consist of a thin stalk. | [84] |
Q9NQ60 | EQTN | Acrosome formation-associated factor isoform 1 | Fertile group only | Acrosomal membrane-anchored protein involved in the process of fertilization and in acrosome biogenesis. | [92] |
Q9UFH2 | DNAH17 | Dynein heavy chain 17, axonemal | ↓ | Force generating protein of respiratory cilia. Produces force towards the minus ends of microtubules. Dynein has ATPase activity; the force-producing power stroke is thought to occur on release of ADP. Involved in sperm motility; implicated in sperm flagellar assembly. | [93] |