aPKC and F-actin Dynamics Promote Hippo Pathway Polarity in Asymmetrically Dividing Neuroblasts

Area of Science:

• Cell Biology
• Developmental Biology
• Signaling Pathways

Background:

• The Hippo signaling pathway typically restricts tissue growth.
• Loss of Hippo pathway components disrupts asymmetric cell division in Drosophila neuroblasts.
• Asymmetric cell division in neuroblasts relies on the apical Par complex localization.

Purpose of the Study:

• To investigate the localization of Hippo pathway components in neuroblasts.
• To understand the regulation of Hippo pathway activity during asymmetric cell division.

Main Methods:

• Immunofluorescence microscopy to visualize protein localization.
• Genetic manipulation of Hippo pathway components and polarity regulators.
• Analysis of F-actin dynamics during neuroblast division.

Main Results:

• Kibra and Salvador, key Hippo pathway activators, were found to polarize to the apical cortex of mitotic neuroblasts.
• Apical polarity, mediated by aPKC, and F-actin dynamics were identified as crucial for Kibra polarization.
• This study elucidates the interplay between apical polarity, the cytoskeleton, and Hippo pathway regulation.

Conclusions:

• Hippo pathway activators exhibit apical polarization in neuroblasts.
• Kibra polarization is regulated by a combination of apical polarity and F-actin dynamics.
• These findings provide mechanistic insights into how the Hippo pathway is controlled during asymmetric neuroblast division.