Pin1 Is Involved in HDAC6-mediated Cancer Cell Motility
INTERNATIONAL JOURNAL OF MEDICAL SCIENCES
Authors: Chuang, Hsiang-Hao; Huang, Ming-Shyan; Wang, Pei-Hui; Liu, Yu-Peng; Hsiao, Michael; Yang, Chih-Jen
Abstract
Histone deacetylase 6 (HDAC6), a member of the HDAC enzymes, has been reported to play substantial roles in many cellular processes. Evidence shows that deregulation of HDAC6 may be involved in the progression of some cancers, neurodegenerative diseases, and inflammatory disorders. However, little is known regarding the effect of post-translational modification of HDAC6 on cellular localization and biological functions. In the present study, we identified four phosphorylation sites on HDAC6 under normal conditions by mass spectrometry analysis. Two phosphorylation sites, pSer22 and pSer412, are recognized as Pin1 (peptidyl-prolyl cis/trans isomerase NIMA-interacting 1) substrates. Pint can interact with HDAC6 and be involved in HDAC6-mediated cell motility. Pint depletion abrogates HDAC6-induced cell migration and invasion in H1299 lung cancer cells. The findings of this study suggest that Pin1 might regulate HDAC6-mediated cell motility through alteration of protein conformation and function. Our results indicate the complexity of activity regulation between HDAC6 and Pin1, expanding knowledge regarding the multifunctional roles of Pin1 in tumorigenesis and cancer progression.
Pin1 mediates A beta(42)-induced dendritic spine loss
SCIENCE SIGNALING
Authors: Stallings, Nancy R.; O'Neal, Melissa A.; Hu, Jie; Kavalali, Ege T.; Bezprozvanny, Ilya; Malter, James S.
Abstract
Early-stage Alzheimer's disease is characterized by the loss of dendritic spines in the neocortex of the brain. This phenomenon precedes tau pathology, plaque formation, and neurodegeneration and likely contributes to synaptic loss, memory impairment, and behavioral changes in patients. Studies suggest that dendritic spine loss is induced by soluble, multimeric amyloid-beta (A beta(42)), which, through postsynaptic signaling, activates the protein phosphatase calcineurin. We investigated how calcineurin caused spine pathology and found that the cis-trans prolyl isomerase Pin1 was a critical downstream target of A beta(42)-calcineurin signaling. In dendritic spines, Pin1 interacted with and was dephosphorylated by calcineurin, which rapidly suppressed its isomerase activity. Knockout of Pin1 or exposure to A beta(42) induced the loss of mature dendritic spines, which was prevented by exogenous Pin1. The calcineurin inhibitor FK506 blocked dendritic spine loss in A beta(42)-treated wild-type cells but had no effect on Pin1-null neurons. These data implicate Pin1 in dendritic spine maintenance and synaptic loss in early Alzheimer's disease.