Basic Research On SAO-1 Regulating Cytoskeleton In The First Cell Division

The SAO-1 protein contains a highly conserved GYF domain.Most of the GYF domain proteins are found in eukaryotes.Previous studies have found that only a few which contain the GYF domain,however,the function of GYF domain contained proteins is still unknown.In this thesis,by constructing the SAO-1 mutant C.elegans,in the embryo stage of C elegans,we explored the regulatory effect of SAO-1 on the cytoskeleton during the first cell division.We found that during the first cell division of the embryo,the depletion of SAO-1 will cause a series of phenotypes,that is the pseudo cleavage furrow to become shallow,the furrow close point near the central point and the centrosome rotation weakening,affecting the first cytoplasmic division.And it affects the developmental survival rate of the embryo.At the same time,the experimental results also show that the depletion of SAO-1 will lead to weakened or no connection between the cell cortex proteins NMY-2 and ANI-1,and break the network structure.The formation and ingression of cleavage furrow are related to the central spindle.These experimental results show to a certain extent that the depletion of SAO-1 breaks the network structure of NMY-2 and ANI-1,and weakens the contractile of the cortex.And then the centrosome rotation weakens,which eventually leads to the shallowness of pseudo cleavage and abnormal furrow close point.Second,we found that during the first cell division,the DLC-1 knockdown phenotype was consistent with the SAO-1 deletion phenotype.Similarly,the knockdown of DLC-1 can break the network structure between NMY-2,ANI-1,and Actin.The contractile force of the cell cortex is weakened,and the centrosome rotation is weakened.A similar phenotype in which the pseudo cleavage becomes shallower and the cleavage closing point is abnormal eventually appears.At the same time,it was found that the depletion of SAO-1 can significantly reduce the expression of DLC-1 in the cytoplasm of embryo,and it was proved by q PCR experiments that the dramatic decrease of DLC-1 expression was not caused by the DLC-1 transcription level.It may be that the degradation or stability of DLC-1 was influenced by SAO-1.Finally,it was found that the destruction of the endoplasmic reticulum structure would lead to uneven distribution of SAO-1 in the cytoplasm;the deletion of SAO-1 or DLC-1 caused the accumulation of endoplasmic reticulum proteins in the cytoplasm and cell cortex.In summary,the results of this thesis indicate that SAO-1 participates in the process of cell division and plays a certain role in the regulation of the cytoskeleton,providing a new perspective for further research on the function of GYF domain proteins.