Arf6 anchors Cdr2 nodes at the cell cortex to control cell size at division.

Fission yeast cells prevent mitotic entry until a threshold cell surface area is reached. The protein kinase Cdr2 contributes to this size control system by forming multiprotein nodes that inhibit Wee1 at the medial cell cortex. Cdr2 node anchoring at the cell cortex is not fully understood.

Fission yeast Pak1 phosphorylates anillin-like Mid1 for spatial control of cytokinesis.

Protein kinases direct polarized growth by regulating the cytoskeleton in time and space and could play similar roles in cell division. We found that the Cdc42-activated polarity kinase Pak1 colocalizes with the assembling contractile actomyosin ring (CAR) and remains at the division site during septation. Mutations in pak1 led to defects in CAR assembly and genetic interactions with cytokinesis mutants.

A mechanism for how Cdr1/Nim1 kinase promotes mitotic entry by inhibiting Wee1.

To enter into mitosis, cells must shut off the cell cycle inhibitor Wee1. SAD family protein kinases regulate Wee1 signaling in yeast and humans. In , two SAD kinases (Cdr1/Nim1 and Cdr2) act as upstream inhibitors of Wee1.

Stable Pom1 clusters form a glucose-modulated concentration gradient that regulates mitotic entry.

Control of cell size requires molecular size sensors that are coupled to the cell cycle. Rod-shaped fission yeast cells divide at a threshold size partly due to Cdr2 kinase, which forms nodes at the medial cell cortex where it inhibits the Cdk1-inhibitor Wee1. Pom1 kinase phosphorylates and inhibits Cdr2, and forms cortical concentration gradients from cell poles.

Cell size-dependent regulation of Wee1 localization by Cdr2 cortical nodes.

Cell size control requires mechanisms that link cell growth with Cdk1 activity. In fission yeast, the protein kinase Cdr2 forms cortical nodes that include the Cdk1 inhibitor Wee1 along with the Wee1-inhibitory kinase Cdr1. We investigated how nodes inhibit Wee1 during cell growth.

Dynamic regulation of Cdr1 kinase localization and phosphorylation during osmotic stress.

Environmental conditions modulate cell cycle progression in many cell types. A key component of the eukaryotic cell cycle is the protein kinase Wee1, which inhibits the cyclin-dependent kinase Cdk1 in yeast through human cells. In the fission yeast , the protein kinase Cdr1 is a mitotic inducer that promotes mitotic entry by phosphorylating and inhibiting Wee1.