Base by Base21 Okt 2025

174: TMEM217–SLC9C1: Wiring the cAMP Switch for Sperm Motility and Male Fertility

️ Episode 174: TMEM217–SLC9C1: Wiring the cAMP Switch for Sperm Motility and Male Fertility

In this episode of PaperCast Base by Base, we explore a PNAS study revealing how TMEM217 forms a complex with the sperm-specific Na+/H+ exchanger SLC9C1 to organize cAMP signaling, sustain motility, and enable fertilization in mice.

Study Highlights:
Using phylogenetic profiling and interactomics, the authors identified TMEM217 as a conserved partner of the exchanger SLC9C1 and showed that both proteins localize to the principal piece of the sperm flagellum. Knockout of Tmem217 produced severe motility defects and infertility with hairpin flagellar bending, accompanied by loss of SLC9C1 and full-length soluble adenylyl cyclase, reduced cAMP levels, and dampened PKA and tyrosine phosphorylation. Co-immunoprecipitation and AlphaFold3 modeling demonstrated that TMEM217 binds the voltage-sensing domain of SLC9C1, supporting a mechanism that assembles the SLC9C1–sAC–cAMP axis during spermiogenesis. Pharmacologic boosting of cAMP paired with membrane-conditioning media restored motility and fertilization in vitro, yielding viable offspring after embryo transfer.

Conclusion:
Dissecting the TMEM217–SLC9C1 interface and local cAMP control suggests diagnostics and mutation-agnostic therapeutic strategies for asthenozoospermia and male infertility.

Reference:
Iida-Norita R, Miyata H, Ninomiya A, Emori C, Kamoshita M, Pan C, Wang H, Ikawa M. Formation of a complex between TMEM217 and the sodium-proton exchanger SLC9C1 is crucial for mouse sperm motility and male fertility. Proceedings of the National Academy of Sciences. 2025;122(42):e2513924122. https://doi.org/10.1073/pnas.2513924122

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
If you'd like to support Base by Base, you can make a one-time or monthly donation here: https://basebybase.castos.com/

Chapters

(00:00:00) - The mystery of athenosomes
(00:02:00) - How SLC9C1 regulates sperm motility
(00:06:43) - Knockout SLC9C1
(00:11:08) - TMP 217 restores sperm to full function
(00:12:35) - Immunity of TMM217 in mammalian sperm
(00:16:03) - Base by base science

Denne episoden er hentet fra en åpen RSS-feed og er ikke publisert av Podme. Den kan derfor inneholde annonser.

Episoder(441)

439: Coembedding Sequence and Structure: CLSS Maps the Protein Universe

Longo LM et al., PNAS - This episode summarizes a PNAS study introducing CLSS, a contrastive two-tower protein language model that coembeds domain sequences, structures, and subsequences into a shared...

11 Aug 23min

438: Mapping AIRE: a proactive atlas of 9,790 missense variants

Axakova A et al., The American Journal of Human Genetics - Axakova et al. generated a variant effect map for AIRE using an insulin‑promoter GFP reporter in HEK293 cells to measure the functional impac...

10 Aug 24min

437: Cell villages and Dirichlet modeling map human cell fitness genetics

Hanson C et al., The American Journal of Human Genetics - Hanson et al. combine pooled multi-donor human neural progenitor cell "villages" with Townlet, a hierarchical Dirichlet regression model, to e...

9 Aug 28min

436: KIAP4 and the ARND family: building the Leishmania adhesion plaque

Owino BO et al., PNAS - Using TurboID proximity proteomics and microscopy, researchers identify KIAP4 as the canonical member of a conserved Adhesion Related NTPase-like Domain (ARND) family that loca...

8 Aug 24min

435: E. coli TGT binds two tRNAs — cryo-EM reveals dual engagement

Ember M et al., PNAS - This episode examines a cryo-EM study of Escherichia coli tRNA-guanine transglycosylase (TGT) that solves the enzyme structure and its covalent intermediate with tRNATyr. Unexpe...

7 Aug 19min

434: High‑coverage genomes recast Japan's prehistoric demography

Ishiya K et al., PNAS - This episode examines a PNAS study that reports two high-coverage ancient human genomes from mainland Japan (an Initial Jomon >67× and a Middle Yayoi >46×). The genomes enable ...

6 Aug 27min

433: Lactate, HSP90α and the Mitochondrial Switch

Wu G et al., Proceedings of the National Academy of Sciences - This episode examines a PNAS study that identifies site-specific lactylation of HSP90α as a metabolic signal linking glycolysis to mitoch...

23 Jul 23min

432: Echovirus 18: Capsid opening releases the genome

Mukhamedova L et al., Proceedings of the National Academy of Sciences - Using cryo-electron tomography and single-particle cryo-EM of infected Cos-7 cells, the authors show that echovirus 18 (E18) rel...

23 Jul 18min