A CDK1 phospho-switch reprograms TRAIP to unload replisomes in mitosis

G Geylani Can (Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.) M Maksym Shyian (Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.) A Archana Krishnamoorthy (Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.) S Samreen Ahmed (Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA.) Y Yang Lim (Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.) A Alex Wu (Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.) R Raphael Pavani (Laboratory of Genome Integrity, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.) M Manal S. Zaher (Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.) A André Nussenzweig M Markus Räschle (Molecular Genetics, Department of Biology, RPTU University Kaiserslautern-Landau, Kaiserslautern, Germany.) T Thomas E. Wilson (Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA.) T Thomas W. Glover (Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA.) J Johannes C. Walter D David Pellman

Abstract

Cells entering mitosis with incompletely replicated DNA face catastrophic chromosome segregation failure. During interphase, the replisome-associated E3 ubiquitin ligase TRAIP ubiquitylates barriers in front of the fork to allow replisome progression. In mitosis, TRAIP is reprogrammed from a  trans -acting to a  cis -acting ligase that can ubiquitylate the replisome itself. This enables the processing of unreplicated DNA by promoting replisome disassembly, fork breakage, and joining of the broken chromosome arms. Here, we describe a mechanism for this reprogramming: the ATPase TTF2 is recruited to the replisome, where its noncatalytic N-terminal domain tethers Cyclin B-CDK1-phosphorylated TRAIP to the leading strand DNA polymerase ε in a geometry that allows replisome ubiquitylation. Thus, a phospho-regulated architectural switch alters replisome organization in mitosis to safeguard genome integrity before chromosome segregation.

Article Details

Journal Science
Volume / Issue Vol. 1, Issue 1
Published July 02, 2026
ISSN 0036-8075
Publisher American Association for the Advancement of Science

Journal Info

Science

American Association for the Advancement of Science

ISSN: 0036-8075 Social Sciences

Authors (14)

G

Geylani Can

Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.

M

Maksym Shyian

Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.

A

Archana Krishnamoorthy

Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.

S

Samreen Ahmed

Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA.

Y

Yang Lim

Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.

A

Alex Wu

Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.

R

Raphael Pavani

Laboratory of Genome Integrity, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.

M

Manal S. Zaher

Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.

A

André Nussenzweig

M

Markus Räschle

Molecular Genetics, Department of Biology, RPTU University Kaiserslautern-Landau, Kaiserslautern, Germany.

T

Thomas E. Wilson

Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA.

T

Thomas W. Glover

Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA.

J

Johannes C. Walter

D

David Pellman