Detection of physical interactions by immunoprecipitation of FLAG- and HA-tagged proteins expressed at the his-3 locus in Neurospora crassa

Protein function is often regulated through interactions with other protein(s) or by post-translational modifications. To understand these mechanisms, it is useful to utilize antibodies. However, it is not always certain whether a good antibody can be made for this purpose. The use of epitope tags eliminates the troubles associated with raising antibodies. In this report, we present a method to detect interactions between proteins by using two types of epitope-tagged proteins, FLAG- and HA-tagged proteins in Neurospora. These constructs were introduced at and expressed from the his-3 locus in different strains. To examine protein-protein interactions, heterokaryons between these strains were constructed. We conclude that this strategy is a useful tool to investigate protein function and protein interactions

Quantum state tomography for Kerr parametric oscillators

Kerr parametric oscillators (KPOs) implemented in the circuit QED architecture can operate as qubits. Their applications to quantum annealing and universal quantum computation have been studied intensely. For these applications, the readout of the state of KPOs is of practical importance. We develop a scheme of state tomography for KPOs with reflection measurement. Although it is known that the reflection coefficient depends on the state of the KPO, it is unclear whether tomography of a qubit encoded into a KPO can be performed in a practical way mitigating decoherence during the measurement, and how accurate it is. We show that the reflection coefficient has a one-to-one correspondence with a diagonal element of the density matrix of the qubit when a probe frequency is properly chosen and an additional single-photon-drive is introduced. Thus, our scheme offers a novel way to readout the qubit along an axis of the Bloch sphere, and therefore the reflection measurement and single-qubit gates can constitute state tomography

Spectroscopic estimation of the photon number for superconducting Kerr parametric oscillators

Quantum annealing (QA) is a way to solve combinational optimization problems. Kerr nonlinear parametric oscillators (KPOs) are promising devices for implementing QA. When we solve the combinational optimization problems using KPOs, it is necessary to precisely control the photon number of the KPOs. Here, we propose a feasible method to estimate the photon number of the KPO. We consider coupling an ancillary qubit to the KPO and show that spectroscopic measurements on the ancillary qubit provide information on the photon number of the KPO

Nicaraven induces programmed cell death by distinct mechanisms according to the expression levels of Bcl-2 and poly (ADP-ribose) glycohydrolase in cancer cells

The PARP-1 expression level and poly (ADP-ribosyl)ation activity in cancer markedly affect the therapeutic outcome. Nicaraven, a free radical scavenger has been found to inhibit PARP, but the effect on cancer cells is still unclear. In this study, we investigated the potential role and molecular mechanism of nicaraven on cancer cells. Using U937 lymphoma cells and HCT-8 colorectal cancer cells, we found that nicaraven moderately reduced the cell viability of both cells in a dose-dependent manner. Interestingly, nicaraven significantly induced apoptosis of U937 cells that are dominantly expressing Bcl-2 but induced PAR-dependent cell death (parthanatos) of HCT-8 cells that are highly expressing poly (ADP-ribose) glycohydrolase (PARG). Based on our data, nicaraven seems to induce programmed cell death through distinct mechanisms, according to the expression levels of Bcl-2 and PARG in cancer cells

Dipyridamole induces the phosphorylation of CREB to promote cancer cell proliferation

Dipyridamole, a traditional anti-platelet drug, has been reported to inhibit the proliferation of cancer cells. The present study aimed to investigate the possibility of dipyridamole as an adjuvant of chemotherapy by enhancing the cytotoxicity of an anti-cancer drug. The cytotoxicity of colorectal cancer cells (HCT-8), CD133+/CD44+ stem-like subpopulation of HCT-8 cells and lymphoma cells (U937) to dipyridamole and/or doxorubicin was evaluated using MTT proliferation and colony forming assays. The expression levels of phosphorylated cAMP-regulatory element-binding protein (pCREB) and poly(ADP-ribose) polymerase-1 (PARP-1) in cells were analyzed via western blotting and immunofluores- cence. The present study reported controversial data regarding the anti-cancer effect of dipyridamole. Dipyridamole increased, rather than inhibited, the proliferation of HCT-8 and U937 cells in a dose-dependent manner. Furthermore, it was found that dipyridamole significantly increased the expression levels of pCREB and PARP-1. However, the combined usage of dipyridamole significantly enhanced the cytotoxicity of doxorubicin to HCT-8 cells at particular doses. Based on the current findings, dipyridamole likely induces the phosphoryla- tion of CREB to promote the proliferation of cancer cells, but may enhance the cytotoxicity of anti-cancer drugs at particular doses

Subaru Hyper Suprime-Cam Survey for An Optical Counterpart of GW170817

We perform a $z$-band survey for an optical counterpart of a binary neutron star coalescence GW170817 with Subaru/Hyper Suprime-Cam. Our untargeted transient search covers $23.6$ deg$^2$ corresponding to the $56.6\%$ credible region of GW170817 and reaches the $50\%$ completeness magnitude of $20.6$ mag on average. As a result, we find 60 candidates of extragalactic transients, including J-GEM17btc (a.k.a. SSS17a/DLT17ck). While J-GEM17btc is associated with NGC 4993 that is firmly located inside the 3D skymap of GW170817, the other 59 candidates do not have distance information in the GLADE v2 catalog or NASA/IPAC Extragalactic Database (NED). Among 59 candidates, 58 are located at the center of extended objects in the Pan-STARRS1 catalog, while one candidate has an offset. We present location, $z$-band apparent magnitude, and time variability of the candidates and evaluate the probabilities that they are located inside of the 3D skymap of GW170817. The probability for J-GEM17btc is $64\%$ being much higher than those for the other 59 candidates ($9.3\times10^{-3}-2.1\times10^{-1}\%$). Furthermore, the possibility, that at least one of the other 59 candidates is located within the 3D skymap, is only $3.2\%$. Therefore, we conclude that J-GEM17btc is the most-likely and distinguished candidate as the optical counterpart of GW170817.Comment: 14 pages, 9 figures. Accepted for publication in PASJ (Publications of the Astronomical Society of Japan