Abstract:

Objectiv  eTo explore the intracellular localization of structural domains in kinesin motor protein Kif18A in eukaryotic cells. Methods  Construct the GFP-expressing plasmids of Kif18A′s wild type and each domain including motor, stalk, tail and motor with part of stalk domain. Then transfect these plasmids into breast cancer cell MCF7 respectively. The GFP-fused proteins were detected by SDS-PAGE and Western blot. Use immunofluorescence staining technique to stain microtubules and DNA in cells. The intracellular localization of GFP-fused proteins was determined under fluorescent microscopy. Results  In interphase cells, GFP-motor domain distributes along microtubules. GFP-tail domain localizes in the nucleus as well as along microtubules and GFP-stalk domain scatters throughout the cytoplasm. In telophase cells, GFP-motor domain still distributes along microtubules. In contrast, GFP-motor with part of stalk domain concentrates on the midbody. Conclusions  The motor and tail domain of Kif18A can both associate with microtubules and the tail domain contained nuclear localization signal (NLS). Only with part of stalk region, motor domain of Kif18A is able to localize on the midbody.

Key words: Human kinesin motor protein Kif18A; Domains; Human breast cancer cell MCF7; Intracellular localization