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Temme, L.

Publications and source records attributed to Temme, L..

3 recordsLinked to original sources
bioRxiv2024

ABHD2 activity is not required for the non-genomic action of progesterone on human sperm

Study questionIs the hydrolase ABHD2 required for progesterone-induced Ca2+ influx via CatSper and the resulting motility responses in human sperm? Summary answerProgesterone-induced Ca2+ influx via CatSper and the resulting motility responses in human sperm do not require ABHD2 activity. What is known alreadySperm motility is tightly regulated by signalling pathways that are activated as sperm ascend the female reproductive tract, including progesterone triggering Ca2+ influx via the CatSper channel and inducing hyperactivated motility needed for fertilization. This process is thought to involve ABHD2, which may hydrolyse the endogenous CatSper inhibitor 2-arachidonoylglycerol (2-AG), thereby relieving inhibition and enabling calcium entry into the flagellum. Study design, size, durationPotent small molecule inhibitors of ABHD2 activity were synthesized, characterized, and used as tools to scrutinize the role of ABHD2 in activation of CatSper and regulation of sperm motility. Participants/materials, setting, methodsDerivatives of published ABHD2 inhibitors were optimised for in vitro potency and cellular activity and subsequently tested in human sperm motility and Ca2+ influx assays. Main results and the role of chanceProgesterone does not activate ABHD2 in vitro. In addition, inhibition of ABHD2 in human sperm has no effect on progesterone-induced Ca2+ influx through CatSper nor on basal or progesterone-induced hyperactivated motility. This demonstrates that ABHD2 activity is, in fact, not required for the non-genomic action of progesterone on human sperm. Large scale datanone Limitations, reasons for cautionWe examined the effects of inhibition of the enzymatic activity of ABHD2. We cannot exclude that ABHD2 functions as a part of a larger multiprotein complex, in which it may play a structural role independent of its hydrolase activity. Wider implications of the findingsThis study presents conclusive evidence that ABHD2 does not bind progesterone and that its hydrolase activity is not required for progesterone activation of CatSper and resulting changes in motility of human sperm. These results highlight the need for further research to elucidate the mechanism underlying the non-genomic action of progesterone on human sperm. Study funding/competing interest(s)This publication is based on research funded by the Gates Foundation. The findings and conclusions contained within are those of the authors and do not necessarily reflect positions or policies of the Gates Foundation. LT, CB, and TS were supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - project numbers 329621271 (CRU326; CB, TS), and 404595355 (Research Training Group "Chemical biology of ion channels (Chembion); LT, TS). This work was funded by the German Federal Ministry of Education and Research (BMBF) within the framework of Contraception Research, grant number 01GR2501A and 01GR2502A. A.A., K.V., A.T., N.D., A.H., M.W. and R.L. are employees of Nuvisan ICB GMBH, Berlin, Germany. Nuvisan is recipient of a Gates Foundation grant. A.A is associate editor of Human Reproduction Open.

cell biology↗
bioRxiv2024

Structures of the human transcription factor brachyury offer insights into DNA recognition, and identify small molecule binders for the development of degraders for cancer therapy

The transcription factor brachyury is a member of the T-Box family of transcription factors. It is active during embryogenesis and is required for the formation of the posterior mesoderm and the notochord in vertebrates. Aside from its role in embryogenesis, brachyury plays an essential role in tumour growth of the rare chordoma bone cancer and is implicated in other solid tumours. Given that brachyury is minimally expressed in healthy tissues, these findings suggest that brachyury is a potential therapeutic target in cancer. Unfortunately, as a ligandless transcription factor, brachyury has historically been considered undruggable. To investigate direct targeting of brachyury by small molecules, we initially determined the structure of human brachyury both in complex with its cognate DNA and in the absence of DNA. Analysis of these structures provided insights into brachyury DNA binding and the structural context of the G177D variant which is strongly associated with chordoma risk. We used these structures to perform a crystallographic fragment screen of brachyury and identify hotspot regions on numerous pockets on the brachyury surface. Finally, we have performed follow-up chemistry on fragment hits and describe the structure-based progression of a thiazole-containing chemical series. Excitingly, we have produced brachyury binders with low {micro}M potency that can serve as starting point for further medicinal chemistry efforts. These data show that brachyury is ligandable and provides an example of how crystallographic fragment screening may be used to find ligands to target protein classes that are traditionally difficult to address using other approaches.

molecular biology↗
bioRxiv2020

Identification and Optimization of cell active 4-anilino-quin(az)oline Inhibitors for Protein Kinase Novel 3 (PKN3)

The development of a small library of 4-anilinoquinolines led to the identification of 7-iodo-N-(3,4,5-trimethoxyphenyl)quinolin-4-amine 16 as a potent inhibitor of Protein Kinase Novel 3 (PKN3) with an IC50 of 1.3 M in cells. Compound 16 presents a useful potential tool compound to study the biology of PKN3 including links to pancreatic and prostate cancer, along with T-cell acute lymphoblastic leukemia. These compounds may be useful tools to explore the therapeutic potential of PKN3 inhibition in prevention of a broad range of infectious and systemic diseases.

pharmacology and toxicology↗