Researchers at the Food and Drug Administration’s Center for Drug Evaluation and the University of Massachusetts-Amherst have shed light on a regulatory pathway in the male reproductive apparatus.  The researchers investigated the role of Hsp90 in relation to testis-specific serine/threonine kinases (TSSKs), expressed in spermatids.

TSSKs are highly involved in the steps following haploid (meiotic) differentiation of spermatid cells as they differentiate into mature spermatozoa, called spermiogenesis.  Hsp90 is known to complex with other chaperones to aid in protein homeostasis and folding, but preferentially associates with signalling molecules, such as kinases and receptors. The researchers used several cell lines, epitope tagging, Hsp90 inhibitors and knockout lines to understand how these TSSKs affect this specific and largely uninvestigated area of sex cell differentiation.

Their experiments showed that inhibition of Hsp90 led to lower TSSK levels.  TSSK4 and 6 were inactivated under these conditions, though TSSK1 and 2 were less so.  Further and more specifically, Hsp90 inhibition led to more TSSKs being degraded through the ubiquitination pathway; suggesting that Hsp90 plays a role therein.  Taken together, the researchers assert that their findings indicate a large and important role of Hsp90 in terms of maintenance and inducement of some of these TSSKs which are necessary for completion of spermatozoa maturation.

The original research paper was published in: The Journal of Biological Chemistry, online, April 18th 2013.

HSP90 functions to stabilize and activate the testis-specific serine/threonine kinases, a family of kinases essential for male fertility.

In this study, two StressMarq products were used: 17-AAG (Hsp90 inhibitor), product#SIH-100A and one of our many Hsp90 antibodies.