PhD Scientific Days 2025

Poster Session II. - B: Molecular Medicine

Investigating Biased Signaling of the AT1 Angiotensin Receptor Using Conformational- and Activation-Based Biosensors

Előadó neve

Dr. Misák Ádám

Neptun code

NHVSC6

Előadó munkahelye

Department of Physiology, Faculty of Medicine, Semmelweis University

Előadó telefonszáma

+36308297793

Előadó e-mail címe

misak.adam@semmelweis.hu

Az előadás címe

Investigating Biased Signaling of the AT1 Angiotensin Receptor Using Conformational- and Activation-Based Biosensors

Szerző(k) neve és munkahelye

Ádám Misák¹, András Dávid Tóth^2,3, Gábor Turu^1,2, László Hunyady^1,4

1: Department of Physiology, Faculty of Medicine, Semmelweis University
2: Institute of Molecular Life Sciences, Centre of Excellence of the Hungarian Academy of Sciences, HUN-REN Research Centre for Natural Sciences
3: Department of Internal Medicine and Haematology, Semmelweis University
4: Institute of Molecular Life Sciences, Centre of Excellence of the Hungarian Academy of Sciences, HUN-REN Research Centre for Natural Sciences,

Bemutatás módja

Poszter

Szekció

Poster Session II. - B: Molecular Medicine

Language of the presentation

Hungarian

Preferred session

Molecular Medicine

Összefoglaló szövege

Investigating Biased Signaling of the AT1 Angiotensin Receptor Using Conformational- and Activation-Based Biosensors
The angiotensin II type 1 receptor (AT1R) is a key regulator of blood pressure and fluid homeostasis, and it is a major therapeutic target for hypertension. Recent research has focused on biased signaling – where ligands selectively activate certain pathways over others – as such agonists may offer therapeutic benefits. However, the mechanism of biased signaling of AT1R remains incompletely understood.
We employed a panel of bioluminescence resonance energy transfer-based biosensors to monitor AT1R signaling across multiple pathways in transiently transfected HEK 293T cells. These included a conformation-sensitive nanobody (Nb.AT110i1)-based and mini G protein biosensors, G protein activation and β-arrestin recruitment sensors, as well as sensors for PIP2 depletion and IP3 production. Various AT1R agonists were tested, with angiotensin II serving as a reference ligand.
We observed distinct receptor conformational- and signaling profiles across agonists, and the conformational signatures induced by the agonists could be linked to their signaling properties. Interestingly, stimulation with the non-peptide AT1R partial agonist L-162,313 led to a unique conformational profile. We found that L-162,313 was able to induce a partial effect in IP3 elevation and PIP2 cleavage, consistent with Gq/11 protein-mediated phospholipase C activation. However, direct measurement of Gq activity with the TRUPATH sensor did not show significant activation upon L-162,313 treatment, indicating that L-162,313 can only weakly stimulate G protein activity. In contrast, we detected robust β-arrestin-2 recruitment to the receptor.
Integrating conformational biosensors with functional assays is a powerful strategy to uncover the mechanistic basis of biased signaling. Our findings suggest that L-162,313 may induce a signaling profile characterized by low Gq/11 activation and maintained β-arrestin recruitment, with the observed IP3 elevation likely originating from the amplification by downstream signaling cascades. These results indicate that L-162,313 should be classified as a β-arrestin–biased AT1R agonist with a hitherto unknown mechanism, and they highlight its potential as a lead compound for the development of novel non-peptide biased ligands.

University

Semmelweis University

Supervisor

Gábor Turu, András Dávid Tóth

Publication of my abstract

I do not give consent to the publication of my abstract on the website of the congress.

phd.section.field

in doctoral studies after complex exam (PhD)

Kind

Szabad

Status

elfogadva

Accepted presentation method

poszter

Előadás fájl jóváhagyás

nem rendelkezett róla

Előadó

7987

Start

18:54

End

19:00