The G1/S transition is promoted by Rb degradation via the E3 ligase UBR5

Summary Mammalian cells make the decision to divide at the G1/S transition in response to diverse signals impinging on the retinoblastoma protein Rb, a cell cycle inhibitor and tumor suppressor. Rb is inhibited by two parallel pathways. In the canonical pathway, Cyclin D-Cdk4/6 kinase complexes phosphorylate and inactivate Rb. In the second, recently discovered pathway, Rb’s concentration decreases during G1 to promote cells progressing through the G1/S transition. However, the mechanisms underlying this second pathway are unknown. Here, we found that Rb’s concentration drop in G1 and recovery in S/G2 is controlled by phosphorylation-dependent protein degradation. In early G1 phase, un- and hypo-phosphorylated Rb is targeted by the E3 ligase UBR5.UBR5knockout cells have higher Rb concentrations in early G1, exhibit a lower G1/S transition rate, and are more sensitive to Cdk4/6 inhibition. This last observation suggests that UBR5 inhibition can strengthen the efficacy of Cdk4/6 inhibitor-based cancer therapies..

Medienart:

Preprint

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

bioRxiv.org - (2024) vom: 15. Apr. Zur Gesamtaufnahme - year:2024

Sprache:

Englisch

Beteiligte Personen:

Zhang, Shuyuan [VerfasserIn]
Valenzuela, Lucas Fuentes [VerfasserIn]
Zatulovskiy, Evgeny [VerfasserIn]
Mangiante, Lise [VerfasserIn]
Curtis, Christina [VerfasserIn]
Skotheim, Jan M. [VerfasserIn]

Links:

Volltext [kostenfrei]

Themen:

570
Biology

doi:

10.1101/2023.10.03.560768

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

XBI041070070