Autophagy-lysosomal system involves highly dynamic membranous components, regulated by several Atg proteins. Recently, a concept of selective autophagy is well accepted, and functions of Atg genes beyond autophagy are suggested. This field also contributes to the understanding of pathophysiological states in various diseases. In this symposium, we will discuss on the autophagy system in light of new aspects or model organisms, predicting new stages of autophagy research.

This symposium will provide several hot topics on molecular and cell biology of microtubule cytoskeleton.

Most macromolecules forming cells are chiral (an object is chiral if it is distinguishable from its mirror image). However, chirality of cells has not been taken into account seriously until very recently. Now, cell chirality is found in structures and functions of cells in vertebrates and invertebrates, such as snails and Drosophila. In addition, proteins required for cell chirality formation just began to be found. In this symposium, researchers studying cell chirality in various systems will come together and discuss the future directions of this novel research field.

Cytokinesis in animal and fungal cells undergoes by contraction of the contractile ring (CR) formed at the division site. The CR is composed mainly of actin filaments and myosin, but it has not well been known how these proteins are recruited to the division site, how they form the CR structure, and how the ring contracts to deform the plasma membrane. Recently, new information on the structure of the CR has been obtained by super-resolution fluorescence microscopy and EM tomography. It has also become possible to reproduce contractile ring-like apparatuses in in vitro systems. Here we introduce new results on cytokinesis obtained by these new techniques.