In mammals, proAKAP4 and AKAP4 are both specifically localized to the fibrous sheath of the principal piece of the flagellum and are largely known to be involved in the flagellum structure and sperm motility (Sergeant et al., 2019)
In mammals, proAKAP4 is synthetized from spermatid stage during spermatogenesis and full stock of proAKAP4 is present in the ejaculated spermatozoa.
Then the pro-AKAP4 precursor is processed to a “mature” AKAP4 protein lacking the 188 first amino acids (Turner et al., 1998) that is playing a central role in flagellar structure, hypermotility, capacitation and fertility (Luconi et al., 2011,Blommaert et al.,2019, Ruelle et al., 2019)
Recently, positive correlations between the amounts of proAKAP4 with key sperm quality and fertility indicators were found in humans, large animals and small mammals (Delehedde et al., 2019)
Examples of AKAP4 and proAKAP4 expressions in bull, horse and pig semen
Bull semen Horse semen
The 4BioDx antibody clone 6F12 (Ref. 4BDX-1701) recognizes the precursor of A-kinase anchor protein 4 (AKAP4) called pro-AKAP4. Western blotting and immunocytochemistry techniques using monoclonal antibodies (clone 6F12) showed that the pro-AKAP4 is specifically expressed in human, equine, porcine, bovine murine and ovine spermatozoa.
The mouse monoclonal antibody clone 7E10 (Ref. 4BDX-1602) recognizes the Carboxy-terminal region of A-kinase anchor protein 4 (AKAP4) and also teh C-Terminus of the pro-AKAP4 (precursor) and is suitable for Western Blot, Immunohistochemistry, Immunofluorescence and electron microscopy.
The 4MID® kits are complete ELISA kits with all reagents and buffers to quantify proAKAP4 in semen samples (fresh, chilled or frozen semen) :