Phosphoproteomics for the identification of new mechanisms of cryodamage: the role of SPATA18 in the control of stallion sperm function†.

This research studied the impacts of cryopreservation on the stallion sperm phosphoproteome, highlighted significant changes, and identified the role of specific proteins and kinases in controlling the functionality and viability of spermatozoa. In essence, cryopreservation was found to cause dephosphorylation of certain proteins, affecting stallion spermatozoa’s viability and functionality.

Overview of Research

• The researchers reanalyzed data from previous studies on the proteomes of fresh and cryopreserved stallion spermatozoa, focusing on the phosphoproteome – specifically proteins that have had a phosphate group added to them.
• Significant changes were observed in the phosphoproteome after cryopreservation, which poses potential implications for the functionality and viability of cryopreserved stallion spermatozoa.

Detailed Findings

• The phosphoproteins most affected by cryopreservation included the calcium binding tyrosine phosphorylation regulated (CABYR), protein kinase cAMP-activated catalytic subunit beta, mitochondria eating protein (SPATA18), A kinase anchoring proteins (AKAP4 and AKAP3), and the Family with sequence similarity 71 member B (FAM71B).
• These proteins are associated with specific gene ontology (GO) terms rebated to sperm structure and functionality: sperm fibrous sheath and sperm principal piece.
• Regulatory interactions between kinases and phosphorylation sites on the proteins were investigated. Potential kinases, based on human orthologs, regulating these phosphoproteins were identified. PKCß was found to be relevant for SPATA18 and GSK3ß for CABYR.
• Through kinase inhibition assays, the study confirmed that these kinases play an important role in activating the aforementioned proteins, suggesting that phosphorylation controls these proteins’ activity and their role in regulating sperm functionality.

Significance of the Findings

• The authors conclude their findings increase understanding about cryodamage in stallion spermatozoa. Specifically, they highlight that cryopreservation induces the dephosphorylation of certain proteins, which subsequently affects sperm functionality and viability.
• This study bridges a knowledge gap in the area of stallion sperm phosphoproteomics, providing insights that could help inform effective cryopreservation strategies and improve fertility outcomes.