17 research outputs found
First observation of excited states in 173Hg
The neutron-deficient nucleus 173Hg has been studied following
fusion-evaporation reactions. The observation of gamma rays decaying from
excited states are reported for the first time and a tentative level scheme is
proposed. The proposed level scheme is discussed within the context of the
systematics of neighbouring neutron-deficient Hg nuclei. In addition to the
gamma-ray spectroscopy, the alpha decay of this nucleus has been measured
yielding superior precision to earlier measurements.Comment: 5 pages, 4 figure
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Structure of LRRK2 in Parkinson's disease and model for microtubule interaction.
Leucine-rich repeat kinase 2 (LRRK2) is the most commonly mutated gene in familial Parkinson's disease1 and is also linked to its idiopathic form2. LRRK2 has been proposed to function in membrane trafficking3 and colocalizes with microtubules4. Despite the fundamental importance of LRRK2 for understanding and treating Parkinson's disease, structural information on the enzyme is limited. Here we report the structure of the catalytic half of LRRK2, and an atomic model of microtubule-associated LRRK2 built using a reported cryo-electron tomography in situ structure5. We propose that the conformation of the LRRK2 kinase domain regulates its interactions with microtubules, with a closed conformation favouring oligomerization on microtubules. We show that the catalytic half of LRRK2 is sufficient for filament formation and blocks the motility of the microtubule-based motors kinesin 1 and cytoplasmic dynein 1 in vitro. Kinase inhibitors that stabilize an open conformation relieve this interference and reduce the formation of LRRK2 filaments in cells, whereas inhibitors that stabilize a closed conformation do not. Our findings suggest that LRRK2 can act as a roadblock for microtubule-based motors and have implications for the design of therapeutic LRRK2 kinase inhibitors
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Structure of LRRK2 in Parkinson's disease and model for microtubule interaction.
Leucine-rich repeat kinase 2 (LRRK2) is the most commonly mutated gene in familial Parkinson's disease1 and is also linked to its idiopathic form2. LRRK2 has been proposed to function in membrane trafficking3 and colocalizes with microtubules4. Despite the fundamental importance of LRRK2 for understanding and treating Parkinson's disease, structural information on the enzyme is limited. Here we report the structure of the catalytic half of LRRK2, and an atomic model of microtubule-associated LRRK2 built using a reported cryo-electron tomography in situ structure5. We propose that the conformation of the LRRK2 kinase domain regulates its interactions with microtubules, with a closed conformation favouring oligomerization on microtubules. We show that the catalytic half of LRRK2 is sufficient for filament formation and blocks the motility of the microtubule-based motors kinesin 1 and cytoplasmic dynein 1 in vitro. Kinase inhibitors that stabilize an open conformation relieve this interference and reduce the formation of LRRK2 filaments in cells, whereas inhibitors that stabilize a closed conformation do not. Our findings suggest that LRRK2 can act as a roadblock for microtubule-based motors and have implications for the design of therapeutic LRRK2 kinase inhibitors
Characterizing the atomic mass surface beyond the proton drip line via alpha-decay measurements of the pi s(1/2) ground state of Re-165 and the pi h(11/2) isomer in Ta-161
The alpha-decay chains originating from the pi s(1/2) and pi h(11/2) states in Au-173 have been investigated following fusion-evaporation reactions. Four generations of alpha radioactivities have been correlated with Au-173(m) leading to a measurement of the alpha decay of Ta-161(m). It has been found that the known alpha decay of Ta-161, which was previously associated with the decay of the ground state, is in fact the decay of an isomeric state. This work also reports on the first observation of prompt gamma rays feeding the ground state of Au-173. This prompt gamma radiation was used to aid the study of the alpha-decay chain originating from the pi s(1/2) state in Au-173. Three generations of alpha decays have been correlated with this state, leading to the observation of a previously unreported activity which is assigned as the decay of Re-165(g). This work also reports the excitation energy of an alpha-decaying isomer in Ta-161 and the Q(alpha) value of the decay of Ta-161(g). DOI:10.1103/PhysRevC.86.06431
Spectroscopy at the two-proton drip line: Excited states in 158W
Excited states have been identified in the heaviest known even-Z isotone 158W, which lies in a region of one-proton emitters and the two-proton drip line. The observation of γ-ray transitions feeding the ground state establishes the excitation energy of the yrast 6+ state confirming the spin-gap nature of the α-decaying 8+ isomer. The 8+ isomer is also expected to be unbound to two-proton emission but no evidence for this decay mode was observed. An upper limit for the two-proton decay branch has been deduced as 0.17% at the 90% confidence level. The possibility of observing two-proton emission from multiparticle isomers in nearby nuclides is considered.peerReviewe