SPANX-A/D protein subfamily plays a key role in nuclear organisation, metabolism and flagellar motility of human spermatozoa

Itziar Urizar-Arenaza, Nerea Osinalde, Vyacheslav Akimov, Michele Puglia, Iraia Muñoa-Hoyos, Marta Gianzo, Jose Antonio Rodriguez, Teresa Ganzabal, Blagoy Blagoev, Irina Kratchmarova, Nerea Subiran*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

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Human sperm protein associated with the nucleus on the X chromosome (SPANX) genes encode a protein family (SPANX-A, -B, -C and -D), whose expression is limited to the testis and spermatozoa in normal tissues and to a wide variety of tumour cells. Present only in hominids, SPANX-A/D is exclusively expressed in post-meiotic spermatids and mature spermatozoa. However, the biological role of the protein family in human spermatozoa is largely unknown. Combining proteomics and molecular approaches, the present work describes the presence of all isoforms of SPANX-A/D in human spermatozoa and novel phosphorylation sites of this protein family. In addition, we identify 307 potential SPANX-A/D interactors related to nuclear envelop, chromatin organisation, metabolism and cilia movement. Specifically, SPANX-A/D interacts with fumarate hydratase and colocalises with both fumarate hydratase and Tektin 1 proteins, involved in meeting energy demands for sperm motility, and with nuclear pore complex nucleoporins. We provide insights into the molecular features of sperm physiology describing for the first time a multifunctional role of SPANX-A/D protein family in nuclear envelope, sperm movement and metabolism, considered key functions for human spermatozoa. SPANX-A/D family members, therefore, might be promising targets for sperm fertility management.

Original languageEnglish
Article number5625
JournalScientific Reports
Number of pages9
Publication statusPublished - 27. Mar 2020

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