Off-campus UMass Amherst users: To download campus access theses, please use the following link to log into our proxy server with your UMass Amherst user name and password.
Non-UMass Amherst users: Please talk to your librarian about requesting this thesis through interlibrary loan.
Theses that have an embargo placed on them will not be available to anyone until the embargo expires.
Title
Characterization of the Role of Testis-Specific Serine Kinase1 (tssk1) in Human Sperm Capacitation
Access Type
Campus Access
Document Type
thesis
Degree Program
Animal Science
Degree Type
Master of Science (M.S.)
Year Degree Awarded
2013
Month Degree Awarded
September
Keywords
kinase, TSSK1, human, sperm, post-translational modification, CASA
Abstract
The ability of a sperm to fertilize an egg involves a complex series of events, referred to as capacitation. Capacitation involves sperm acquiring a hyperactive state of motility and the ability to undergo an exocytotic process called the acrosome reaction (AR). Molecular intervention of cell signaling pathways involved in sperm capacitation has been proposed as a way for developing novel male contraceptives.
Testis-specific serine kinase1 (TSSK1) is a novel protein in the calcium/calmodulin superfamily of human kinases, and has the potential for targeted inhibition to provide a highly safe and effective form of male contraception. It is expressed post-meiotically during spermatogenesis, and is localized to the head and tail of the mature sperm. Tssk1/Tssk2 knockout (KO) mouse models have demonstrated that these proteins are necessary for sperm function as deletion of these genes have rendered male mice infertile. Studies presented here involve the investigation of the biochemical regulation of TSSK1 and its role in human sperm capacitation.
Posttranslational modification of TSSK1 was analyzed in capacitated human sperm in the presence or absence of AR inducers in vitro. Furthermore, experimental conditions were tested for measuring TSSK1 enzymatic activity in capacitated human sperm, and TSSK1 kinase activity was further correlated to the observed phosphorylation/dephosphorylation.
Lastly, a computer-aided sperm analysis (CASA) protocol for assessing human sperm motility was standardized. Human sperm cell subpopulations were evaluated under different sperm capacitating conditions, and a Boolean argument was created to quantify progressive and non-progressive hyperactive cells. Determining TSSK1’s regulation by posttranslational modifications will help further characterize this protein as a potential target for inhibition and, ultimately, for use as a novel technique of male contraception. Improved conditions for human sperm analysis by CASA may provide a tool for assessing a potential role of TSSK1 in human sperm motility and hyperactivation.
DOI
https://doi.org/10.7275/4135875
First Advisor
Ana Maria Salicioni