PhD Scientific Days 2025

Poster Session III. - C: Molecular Medicine

CXCR-Mediated β-Arrestin Recruitment - Identifying Non-Receptor Interactions

Előadó neve

Dr. Kis Katalin

Neptun code

YG6XR9

Előadó munkahelye

Semmelweis Egyetem Élettani Intézet

Előadó telefonszáma

+36307513269

Előadó e-mail címe

kis0608@gmail.com

Az előadás címe

CXCR-Mediated β-Arrestin Recruitment - Identifying Non-Receptor Interactions

Szerző(k) neve és munkahelye

Dr. Katalin Kis¹

1: Semmelweis Egyetem Élettani Intézet

Bemutatás módja

Poszter

Szekció

Poster Session III. - C: Molecular Medicine

Language of the presentation

Hungarian

Preferred session

Molecular Medicine

Összefoglaló szövege

Introduction
β-arrestin recruitment to G protein-coupled receptors (GPCRs) is governed by specific phosphorylation patterns. High-affinity interactions between AT1R and β-arrestin2 rely on 'stability locks' (Tóth et al., 2018), where β-arrestin2 residues K11 and K12 engage phosphorylated Ser/Thr sites within the receptor's C-terminal domain. We identified a conserved motif—ArreSTick (Tóth et al. 2024.)—that facilitates stable β-arrestin interactions. This motif is also present in numerous non-receptor proteins. We found that HTSF1, a transcription factor linked to HIV replication, binds β-arrestin2 via phosphorylation. Expanding this research, we now investigate HIV-related receptors, CXCR4 and CCR5 which contains the conserved Ser/Thr pattern.
Aims
Our goals were to identify non-receptor β-arrestin partners and determine how CXCR activation influences their interaction. We also aimed to optimize β-arrestin membrane recruitment to reduce background and enable downstream proteomic analysis.
Methods
We applied BRET assays and confocal microscopy to study β-arrestin binding in CXCR4- or CXCR7-expressing cells, with or without CXCL12 stimulation. We assessed the effect of co-expressing various GRKs and a dominant-negative dynamin mutant on phosphorylation and β-arrestin recruitment, comparing unstimulated and stimulated states.
Results
CXCR4 showed constitutive β-arrestin interaction, absent in the K2A β-arrestin mutant, indicating basal phosphorylation. CXCR7 lacked basal activity but recruited β-arrestin upon ligand binding. The strongest recruitment occurred with dynamin co-expression, suggesting increased internalization and signaling potential.
Conclusion
The CXCR7–dynamin system offers low baseline and strong stimulus-dependent β-arrestin recruitment, making it ideal for mass spectrometry and downstream signaling studies.
Funding
This work was supported by the Hungarian National Research, Development, and Innovation Fund (NKFI FK 138862, K 139231, ADVANCED_2024 151284) and by the SE 250+ Excellence PhD Scholarship.

kis.katalin@stud.semmelweis.hu
Semmelweis Egyetem
Dr. Turu Gábor

University

Semmelweis University

Supervisor

Dr Turu Gábor

Publication of my abstract

I give consent to the publication of my abstract on the website of the congress.

Kind

Szabad

Status

elfogadva

Accepted presentation method

poszter

Előadás fájl jóváhagyás

nem rendelkezett róla

Előadó

9143

Start

15:06

End

15:12