PKCζ regulates cell polarisation and proliferation restriction during mammary acinus formation

Author:

Whyte Jacqueline1,Thornton Laura1,McNally Sara1,McCarthy Sarah1,Lanigan Fiona1,Gallagher William M.1,Stein Torsten2,Martin Finian1

Affiliation:

1. UCD Conway Institute and School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland

2. Division of Cancer Sciences and Molecular Pathology, Section of Pathology and Gene Regulation, University of Glasgow, Glasgow, G11 6NT, Scotland, UK

Abstract

Mammary epithelial cells organize in three dimensions and generate acini when supported on laminin-rich extracellular matrix. Acinus formation begins with the apicobasal polarisation of the outer cells of the assembly and the withdrawal of these cells from the cell cycle. Internal cells then clear out to form a hollow lumen. Here, we show that PKCζ is phosphorylated (at T410) and activated in the early stages of acinus formation in both primary cells and MCF10A cells, and during mammary tree maturation in vivo. Phospho-PKCζ colocalised with tight junction components and bound to the Par polarising complex in developing acini. To further investigate the importance of PKCζ phosphorylation in this context, acinus formation was studied in MCF10A cells overexpressing non-phosphorylatable (T410A) or ‘constitutively phosphorylated’ (T410E) PKCζ. In both cell types, acinus-associated cell polarisation and lumen clearance were compromised, emphasising the importance of regulated phosphorylation of PKCζ at T410 for successful acinus formation. PKCζ can be activated in a phosphorylation (at T410)-dependent and a phosphorylation-independent manner. Cells overexpressing a complete kinase-deficient PKCζ (K281W) displayed a cell polarising deficit, but also generated large ‘multi-acinar’ structures with associated early lumenal cell hyperproliferation. Therefore our data shows, for the first time, that two separable PKCζ activities (one phosphorylation-dependent, the other not) are required to support the cell polarisation and proliferation restriction that underpins successful acinus formation. Paralleling these contributions, we found that low levels of PKCζ mRNA expression are associated with more ‘poorly differentiated’ tumours and a poor outcome in a cohort of 295 breast cancer patients.

Publisher

The Company of Biologists

Subject

Cell Biology

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3