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Human TAO kinase 1 induces apoptosis in SH‐SY5Y cells
Author(s) -
Wu MingFang,
Wang ShyangGuang
Publication year - 2008
Publication title -
cell biology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.932
H-Index - 77
eISSN - 1095-8355
pISSN - 1065-6995
DOI - 10.1016/j.cellbi.2007.08.006
Subject(s) - transfection , kinase , microbiology and biotechnology , dapi , apoptosis , sh sy5y , biology , cyclin dependent kinase 9 , cell culture , mitogen activated protein kinase kinase , chemistry , protein kinase a , biochemistry , gene , neuroblastoma , genetics
The human TAO kinase 1 (hTAOK1) is a member of the Ste20 group of kinases with the kinase domain located at the N‐terminus. The rat homologue, originally named TAO1, has been demonstrated to be highly expressed in brain. In this study, the human TAO kinase 1 was transfected into human neuroblastoma SH‐SY5Y cells and its biological effects on the cell morphology were observed by co‐expressing the enhanced green fluorescent protein (EGFP). It was found that after 16 h of transfection the cells had shrunk, and finally became rounded when transfected with wild‐type or mutant K57A genes encoding either the kinase domain (residues 1–376) or the full‐length molecule (residues 1–1001). Thirty‐four hours after transfection, cells floated and apoptotic bodies were observed after nuclear staining with DAPI. On the other hand, the cells that were transfected with the gene encoding the C‐terminal regulatory region (residues 377–1001) of hTAOK1, appeared to remain unchanged. In order to know the signaling events involved in the above biological phenomena, caspase‐3‐like activities of the transfected cells were measured in the absence or presence of JNK inhibitor SP600125, in which caspase‐3 and JNK (C‐jun‐N‐terminal kinase) are both known to be critical components of the neuronal apoptosis. The results showed that the apoptotic cells exhibited elevated caspase‐3‐like activity, which could be reduced by SP600125 to some extent. It is concluded that human TAO kinase 1 induces apoptosis in SH‐SY5Y cells and the kinase domain is essential, but its catalytic activity seems to be dispensable in this case.