Hormone secretion by pituitary cells is decreased by roscovitine, an inhibitor of cyclin-dependent kinase 5 (Cdk5). Roscovitine treatment reorganizes cortical actin and ultrastructural analysis demonstrates that roscovitine limits the ability of secretory granules to approach the plasma membrane or one another. Trio, a multifunctional RhoGEF expressed in pituitary cells, interacts with peptidylglycine α-amidating monooxygenase, a secretory granule membrane protein known to affect the actin cytoskeleton. Roscovitine inhibits the ability of Trio to activate Rac, and peptides corresponding to the Cdk5 consensus sites in Trio are phosphorylated by Cdk5. Together, these data suggest that control of the cortical actin cytoskeleton, long known to modulate hormone exocytosis and subsequent endocytosis, involves Cdk5-mediated activation of Trio.
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Special Issue – Cell Biology of Mitochondria
Our special issue on ‘Cell Biology of Mitochondria’ is now complete. Explore this issue and read the Editorial from our Guest Editors Ana J. García-Sáez and Heidi McBride.
Save the date – Imaging Cell Dynamics
We are delighted to announce that we will be hosting a 2026 Imaging Cell Dynamics meeting. This meeting will provide a unique opportunity to bring together experts working at the interface between cell biology and imaging. Save the date for 11-14 May 2026 and register for more information.
Origin and evolution of mitochondrial inner membrane composition
In this Review, Kailash Venkatraman and colleagues provide an examination of the morphological similarities between prokaryotic intracytoplasmic membranes and mitochondrial inner membranes, and whether cristae evolution has driven specialisation of the mitochondrial lipidome.
Resolution in super-resolution microscopy
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