Deletion of the ABL SH3 domain reactivates de-oligomerized BCR-ABL for growth factor independence

AbstractBiological activities of BCR-ABL, an activated tyrosine kinase oncogene responsible for pathogenesis of human leukemias, can be completely inactivated by a deletion of the BCR aminoterminal sequence with a tetramerizing property (BCR-ABL Δ1–40). We attempted several ways to restore the ability to induce growth factor independence to the de-oligomerized BCR-ABL Δ1–40 and found that an additional deletion of the ABL SH3 domain could. In BCR-ABL Δ1–40 reactivated by the SH3 deletion, transphosphoryation of other cellular proteins like p62 or SHC in vivo and autophosphorylation with recruitment of GRB-2 were also recovered

Nuclear export of the influenza virus ribonucleoprotein complex: Interaction of Hsc70 with viral proteins M1 and NS2

The influenza virus replicates in the host cell nucleus, and the progeny viral ribonucleoprotein complex (vRNP) is exported to the cytoplasm prior to maturation. NS2 has a nuclear export signal that mediates the nuclear export of vRNP by the vRNP-M1-NS2 complex. We previously reported that the heat shock cognate 70 (Hsc70) protein binds to M1 protein and mediates vRNP export. However, the interactions among M1, NS2, and Hsc70 are poorly understood. In the present study, we demonstrate that Hsc70 interacts with M1 more strongly than with NS2 and competes with NS2 for M1 binding, suggesting an important role of Hsc70 in the nuclear export of vRNP

Arg tyrosine kinase is involved in homologous recombinational DNA repair

金沢大学がん研究所c-Abl plays important roles in cellular response to DNA damage. However, possible roles for Arg (Abl-related gene) in DNA damage response are unknown. Here, we show that ionizing radiation (IR)-induced Rad51 focus formation is reduced in Arg-deficient cells generated from a chicken B cell line by targeted disruption. This is consistent with the findings that Arg-deficient cells display hypersensitivity to IR, elevated frequencies of IR-induced chromosomal aberrations, and reduced targeted integration frequencies. All of these abnormalities in DNA damage repair are also observed in ATM-deficient cells but not in c-Abl-deficient cells. Finally, we show that Arg interacts with and phosphorylates Rad51 in 293T cells. These results suggest that Arg plays a role in homologous recombinational (HR) DNA repair by phosphorylating Rad51

Secondary Publication: COVID-19 Pandemic: Drug Development and Treatment

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in late 2019. It has been rapidly spreading worldwide ever since. The majority of COVID-19 infections are asymptomatic or mildly symptomatic. However, old age or comorbidities can result in a cytokine storm, which eventually leads to death. To date, no drug has been clinically proven effective to treat COVID-19, and development of effective drugs against SARS-CoV-2 is urgently required. Several drugs used in treating other diseases are being evaluated. Clinical trials on many new antiviral drugs and vaccine candidates are also rapidly ongoing. In this review, we summarized the currently used drugs and newly developed vaccines for the treatment of COVID-19

Ligand-independent activation of vascular endothelial growth factor receptor 1 by low-density lipoprotein

Elevated serum low-density lipoprotein (LDL) is a risk factor for atherosclerotic disorders. However, prominent atherosclerosis, which has been observed in LDL receptor (LDLR)-knockout mice, has diminished the significance of LDLR as a cause of atherosclerosis, while elaborate studies have focused on the receptors for denatured LDL. Here we report that native LDL (nLDL) activates vascular endothelial growth factor (VEGF) receptor 1 (VEGFR1) but not VEGFR2 through LDLR and is as potent as VEGF in macrophage migration. Binding and co-endocytosis of VEGFR1 and LDLR were enhanced by nLDL, which is concomitant with ubiquitination-mediated degradation of VEGFR1. We propose that LDLR-mediated use of VEGFR1 by nLDL could be a potential therapeutic target in atherosclerotic disorders