Sequence-dependent abnormal aggregation of human Tau fragment in an inducible cell model.
A pathological hallmark of Alzheimer disease (AD) is the accumulation of misfolded hyperphosphorylated microtubule-associated protein Tau within neurons, forming neurofibrillary tangles and leading to synaptic dysfunction and neuronal death. Here we study sequence-dependent abnormal aggregation of human fragment Tau244-372 in an inducible cell model. As evidenced by confocal laser scanning microscopy, Western blot, and immunogold electron microscopy, fibril-forming motifs are essential and sufficient for abnormal aggregation of Tau244-372 in SH-SY5Y neuroblastoma cells induced by Congo red: when its two fibril-forming segments PHF6 and PHF6* are deleted, Tau244-372 does lose its ability to form fibrils in SH-SY5Y cells, and the replacement of PHF6 and PHF6* with an unrelated amyloidogenic sequence IFQINS from human lysozyme does rescue the fibril-forming ability of Tau244-372 in SH-SY5Y cells. By contrast, insertion of a non-fibril forming peptide GGGGGG does not drive the disabled Tau244-372 to misfold in SH-SY5Y cells. Furthermore, as revealed by quantum dots based probes combined with annexin V staining, annexin V-FITC apoptosis detection assay, and immunofluorescence, fibril-forming motifs are essential and sufficient for early apoptosis of living SH-SY5Y cells induced by abnormal aggregation of Tau244-372. Our results suggest that fibril-forming motifs could be the determinants of Tau protein tending to misfold in living cells, thereby inducing neuronal apoptosis and causing the initiation and development of AD.
State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Xiao-Ling
XL
Liu
State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Ji-Ying
JY
Hu
State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Meng-Yun
MY
Hu
State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Yi
Y
Zhang
College of Chemistry and Molecular Sciences, State Key Laboratory of Virology, Wuhan University, Wuhan 430072, China.
Zheng-Yuan
ZY
Hong
State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Xiao-Qing
XQ
Cheng
State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Jie
J
Chen
College of Chemistry and Molecular Sciences, State Key Laboratory of Virology, Wuhan University, Wuhan 430072, China.
Dai-Wen
DW
Pang
State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China. Electronic address: liangyi@whu.edu.cn.
Yi
Y
Liang
D000544:Alzheimer Disease / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence / Q000502:physiology; D045744:Cell Line, Tumor; D057809:HEK293 Cells; D006801:Humans; D008954:Models, Biological; D016254:Mutagenesis, Insertional / Q000502:physiology; D016874:Neurofibrillary Tangles / Q000235:genetics / Q000378:metabolism; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D066263:Protein Aggregation, Pathological / Q000235:genetics / Q000378:metabolism; D017510:Protein Folding; D054730:Protein Interaction Domains and Motifs / Q000235:genetics; D017384:Sequence Deletion / Q000502:physiology; D014162:Transfection; D015854:Up-Regulation / Q000235:genetics; D016875:tau Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism*
D010446:Peptide Fragments; D016875:tau Proteins
Alzheimer disease; Apoptosis; Fibril-forming motif; Protein aggregation; Tau protein