Investigate the Function of Kinectin Isoforms in Endoplasmic Reticulum Dynamics

Abstract

The function of kinectin isoforms during ER dynamcis was addressed in this project using multiple molecular and cellular imaging techniques. The subcellular localization of kinectin isoforms was studied by injecting EGFP-tagged chimera into a DsRed-ER HeLa line. Confocal microscopy imaging revealed significant co-localization of 160 kDa kinectin with ER and diffused distribution pattern for 120 kDa isoforms. In addition, 160 kDa isoforms with Int4 co-accumulated with ER in the leading edges of migrating cells. RNAi and overexpression studies further confirmed that 160 kDa kinectin with Int4 anchored ER to kinesin which then contributed to cell migration by transporting ER to the leading edge along microtubles. The importance of kinectin in ER dynamics during cell division was also investigated using morpholinos which specifically knocked down Int4. However, neither the overall ER dynamics nor the association with spindle was affected, indicating ER dynamics during mitosis might be independent of kinesin-kinectin interaction.