aPKC: the Kinase that Phosphorylates Cell Polarity

Area of Science:

• Cell Biology
• Molecular Biology
• Biochemistry

Background:

• Cell polarity establishment and maintenance rely on complex, regulated protein interactions.
• Phosphorylation is a key regulatory mechanism controlling protein function and localization.
• Atypical protein kinase C (aPKC) is a central kinase in cell polarity research with numerous identified downstream substrates.

Purpose of the Study:

• To review the role of aPKC in regulating cell polarity.
• To discuss aPKC substrates and the mechanisms by which phosphorylation controls their functions and localization.
• To highlight recent advances in understanding the spatial and temporal regulation of aPKC activity.

Main Methods:

• Literature review of studies on aPKC in cell polarity.
• Analysis of aPKC's role in anterior-posterior polarity (C. elegans), apical-basal polarity (epithelial cells), and asymmetric division (Drosophila neuroblasts).
• Examination of molecular mechanisms controlling aPKC localization and activity.

Main Results:

• Over half of essential polarity proteins are identified as aPKC substrates.
• aPKC phosphorylation significantly impacts protein subcellular localization and biological functions.
• Studies reveal intricate spatial and temporal control mechanisms governing aPKC.

Conclusions:

• aPKC is a pivotal regulator of cell polarity across diverse biological systems.
• Phosphorylation by aPKC is a primary mechanism for controlling polarity protein dynamics.
• Understanding aPKC regulation offers insights into fundamental cell biology processes.