Hana Huang

Magnetic entropy change larger than that of gadolinium has been observed in polycrystalline of La 1-x Ca x MnO 3 ( x = 0.2 and 0.33) perovskite-type manganese oxide. The large magnetic entropy change produced by the abrupt reduction of magnetization is attributed to the ...

ABSTRACT: A new type of hybrid material incorporating poly(dimethylsi1oxane) (PDMS) with tetraeth-oxysilane (TEOS) has been successfully produced by using a sol-gel process. This material showed good optical transparency and very different mechanical behavior ...

Parkinson's disease is a common neurodegenerative disorder in which familial-linked genes have provided novel insights into the pathogenesis of this disorder. Mutations in Parkin, a ring-finger-containing protein of unknown function, are implicated in the pathogenesis of autosomal recessive familial Parkinson's disease. Here, we show that Parkin binds to the E2 ubiquitin-conjugating human enzyme 8 (UbcH8) through its C-terminal ring-finger. Parkin has ubiquitin-protein ligase activity in the presence of UbcH8. Parkin also ubiquitinates itself and promotes its own degradation. We also identify and show that the synaptic vesicle-associated protein, CDCrel-1, interacts with Parkin through its ring-finger domains. Furthermore, Parkin ubiquitinates and promotes the degradation of CDCrel-1. Familial-linked mutations disrupt the ubiquitin-protein ligase function of Parkin and impair Parkin and CDCrel-1 degradation. These results suggest that Parkin functions as an E3 ubiquitin-protein ligase through its ring domains and that it may control protein levels via ubiquitination. The loss of Parkin's ubiquitin-protein ligase function in familial-linked mutations suggests that this may be the cause of familial autosomal recessive Parkinson's disease.