Repository logo
 

Phosphoinositide 3-kinase beta controls replication factor C assembly and function.

Published version
Peer-reviewed

Type

Article

Change log

Authors

Redondo-Muñoz, Javier  ORCID logo  https://orcid.org/0000-0003-0607-2171
Rodríguez, María Josefa 
Silió, Virginia 
Pérez-García, Vicente  ORCID logo  https://orcid.org/0000-0001-5594-1607
Valpuesta, José María  ORCID logo  https://orcid.org/0000-0001-7468-8053

Abstract

Genomic integrity is preserved by the action of protein complexes that control DNA homeostasis. These include the sliding clamps, trimeric protein rings that are arranged around DNA by clamp loaders. Replication factor C (RFC) is the clamp loader for proliferating cell nuclear antigen, which acts on DNA replication. Other processes that require mobile contact of proteins with DNA use alternative RFC complexes that exchange RFC1 for CTF18 or RAD17. Phosphoinositide 3-kinases (PI3K) are lipid kinases that generate 3-poly-phosphorylated-phosphoinositides at the plasma membrane following receptor stimulation. The two ubiquitous isoforms, PI3Kalpha and PI3Kbeta, have been extensively studied due to their involvement in cancer and nuclear PI3Kbeta has been found to regulate DNA replication and repair, processes controlled by molecular clamps. We studied here whether PI3Kbeta directly controls the process of molecular clamps loading. We show that PI3Kbeta associated with RFC1 and RFC1-like subunits. Only when in complex with PI3Kbeta, RFC1 bound to Ran GTPase and localized to the nucleus, suggesting that PI3Kbeta regulates RFC1 nuclear import. PI3Kbeta controlled not only RFC1- and RFC-RAD17 complexes, but also RFC-CTF18, in turn affecting CTF18-mediated chromatid cohesion. PI3Kbeta thus has a general function in genomic stability by controlling the localization and function of RFC complexes.

Description

Keywords

Amino Acid Motifs, Animals, Cell Line, Cell Nucleus, Class Ia Phosphatidylinositol 3-Kinase, DNA Repair, DNA Replication, Humans, Protein Subunits, Replication Protein C, ran GTP-Binding Protein

Journal Title

Nucleic Acids Res

Conference Name

Journal ISSN

0305-1048
1362-4962

Volume Title

41

Publisher

Oxford University Press (OUP)