Fluorescence fluctuation analysis reveals PpV dependent Cdc25 protein dynamics in living embryos

The protein phosphatase Cdc25 is a key regulator of the cell cycle by activating Cdk-cyclin complexes. Cdc25 is regulated by its expression levels and post-translational mechanisms. In early Drosophila embryogenesis, Cdc25/Twine drives the fast and synchronous nuclear cycles. A pause in the cell cycle and the remodeling to a more generic cell cycle mode with a gap phase are determined by Twine inactivation and destruction in early interphase 14, in response to zygotic genome activation. Although the pseudokinase Tribbles contributes to the timely degradation of Twine, Twine levels are controlled by additional yet unknown post-translational mechanisms. Here, we apply a non-invasive method based on fluorescence fluctuation analysis (FFA) to record the absolute concentration profiles of Twine with minute-scale resolution in single living embryos. Employing this assay, we found that Protein phosphatase V (PpV), the homologue of the catalytic subunit of human PP6, ensures appropriately low Twine protein levels at the onset of interphase 14. PpV controls directly or indirectly the phosphorylation of Twine at multiple serine and threonine residues as revealed by phosphosite mapping. Mutational analysis confirmed that these sites are involved in control of Twine protein dynamics, and cell cycle remodeling is delayed in a fraction of the phosphosite mutant embryos. Our data reveal a novel mechanism for control of Twine protein levels and their significance for embryonic cell cycle remodeling.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:16

Enthalten in:

PLoS genetics - 16(2020), 4 vom: 07. Apr., Seite e1008735

Sprache:

Englisch

Beteiligte Personen:

Liu, Boyang [VerfasserIn]
Gregor, Ingo [VerfasserIn]
Müller, H-Arno [VerfasserIn]
Großhans, Jörg [VerfasserIn]

Links:

Volltext

Themen:

Cell Cycle Proteins
Drosophila Proteins
EC 2.7.11.1
EC 3.1.3.16
Journal Article
Nuclear Proteins
Phosphoprotein Phosphatases
Protein Serine-Threonine Kinases
Protein phosphatase 5
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Trbl protein, Drosophila
Twe protein, Drosophila

Anmerkungen:

Date Completed 03.08.2020

Date Revised 14.02.2024

published: Electronic-eCollection

Citation Status MEDLINE

doi:

10.1371/journal.pgen.1008735

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM308367626