Journal of Cell Biology I The team of Professor Xuebiao Yao of the University of Science and Technology of China discovered a new mechanism of polar growth regulation of asymmetric cell division

Cells are the most basic units of life activity, and cell polarity (i.
e.
, asymmetry) is one of the important features of
epithelial cell function.
The establishment and maintenance of cell polarity plays a key role
in basic life processes such as cell migration and asymmetric cell division.
For example, cell polarity establishes and maintains the spatial and temporal distribution of determinants that regulate cell fate, which in turn regulates the asymmetric division
of stem cells.
However, the role of cell membrane properties in the establishment and maintenance of cell polarity remains unclear
.
Aiming at the molecular mechanism of cell polarity formation, Professor Fu Chuanxi's research group systematically analyzed the protein machinery of cell polarity formation, and combined the use of model system fission yeast and mammalian cells to reveal the dynamics of cell substructure and its mechanism of regulating cell fate
.
The research group successively discovered multiple key cell life activity regulatory proteins, including the Septin cytoskeletal plasma membrane localization regulatory protein Rga6 (Zheng et al.
, 2022J Cell Sci ), the protein Emr1, which regulates mitochondrial and endoplasmic reticulum interactions (Faiz et al.
, 2021Nat Commun), Klp2, a kinesin that specifically regulates meiotic spindle assembly (Zheng et al.
, 2020J Biol Chem), et al.

In view of the biological significance of GAP protein of Cdc42 in the process of cell polarity formation, the research team first established a model system for using fission yeast spores to study asymmetric cell division.
The model system was used to carry out genetic screening analysis based on live-cell microscopy, and the rga6 gene (GAP protein encoding Cdc42) was found The knockout of spore cells resulting in unipolar growth exhibits an abnormal bipolar growth phenotype
.
Further studies have shown that unipolar cell growth relies on the asymmetric distribution of Rga6 on the cytoplasmic membrane, and the phospholipid molecule PI(4,5)P2 on the cytoplasmic membrane determines the asymmetric distribution
of Rga6 on the cytoplasmic membrane.
Therefore, this work shows that the asymmetric distribution of phospholipids in the cytoplasmic membrane regulates the localization of GAP protein on the cytoplasmic membrane, thereby mediating the polar growth
of specific cells.
The research results, titled "The Cdc42 GAP Rga6 promotes monopolaroutgrowth of spores", were published in November Published online on the 10th in the Journal of Cell Biology, a key journal of cell biology, it provides new insights
for understanding the establishment and maintenance of cell polarity.

Wei Wenfan, a postdoctoral fellow in the Department of Life Sciences and Medicine at the University of Science and Technology of China, and Zheng Biyu, a doctoral student, are the co-first authors of the paper, and Professor Fu Chuanzi and Professor Yao Xuebiao are the co-corresponding authors
of the paper.

This work has been strongly supported by the Key Laboratory of Cell Dynamics of the Ministry of Education and the Department of Molecular and Cellular Biophysics of the Hefei National Research Center for Microscale, and supported
by the National Key Research and Development Program of China and the National Natural Science Foundation of China.

Article Links:

https://rupress.
org/jcb/article-abstract/222/1/e202202064/213678/The-Cdc42-GAP-Rga6-promotes-monopolar-outgrowth-of?redirectedFrom=fulltext