Cullin-3 and its adaptor protein ANKFY1 determine the surface level of integrin β1 in endothelial cells

Angiogenesis, the formation of new blood vessels from the pre-existing vasculature, is related to numerous pathophysiological events. We previously reported that a RING ubiquitin ligase complex scaffold protein, cullin-3 (CUL3), and one of its adaptor proteins, BAZF, regulated angiogenesis in the mouse retina by suppressing Notch signaling. However, the degree of inhibition of angiogenesis was made greater by CUL3 depletion than by BAZF depletion, suggesting other roles of CUL3 in angiogenesis besides the regulation of Notch signaling. In the present study, we found that CUL3 was critical for the cell surface level of integrin β1, an essential cell adhesion molecule for angiogenesis in HUVECs. By siRNA screening of 175 BTBPs, a family of adaptor proteins for CUL3, we found that ANKFY1/Rabankyrin-5, an early endosomal BTBP, was also critical for localization of surface integrin β1 and angiogenesis. CUL3 interacted with ANKFY1 and was required for the early endosomal localization of ANKFY1. These data suggest that CUL3/ANKFY1 regulates endosomal membrane traffic of integrin β1. Our results highlight the multiple roles of CUL3 in angiogenesis, which are mediated through distinct CUL3-adaptor proteins

Encapsulation of Two Potassium Cations in Preyssler-Type Phosphotungstates: Preparation, Structural Characterization, Thermal Stability, Activity as an Acid Catalyst, and HAADF-STEM Images

Dipotassium cation (K⁺)-encapsulated Preyssler-type phosphotungstate, [P₅W₃₀O₁₁₀K₂]^13‑, was prepared by heating monobismuth (Bi³⁺)-encapsulated Preyssler-type phosphotungstate, [P₅W₃₀O₁₁₀Bi­(H₂O)]^12‑, in acetate buffer in the presence of an excess amount of potassium cations. Characterization of the isolated potassium salt, K₁₃[P₅W₃₀O₁₁₀K₂] (<b>1a</b>), and its acid form, H₁₃[P₅W₃₀O₁₁₀K₂] (<b>1b</b>), by single crystal X-ray structure analysis, ³¹P and ¹⁸³W nuclear magnetic resonance (NMR), Fourier transform infrared (FT-IR) spectroscopy, cyclic voltammetry (CV), high-resolution electrospray ionization mass spectroscopy (HR-ESI-MS), and elemental analysis revealed that two potassium cations are encapsulated in the Preyssler-type phosphotungstate molecule with formal <i>D</i>_5<i>h</i> symmetry, which is the first example of a Preyssler-type compound with two encapsulated cations. Incorporation of two potassium cations enhances the thermal stability of the potassium salt, and the acid form shows catalytic activity for hydration of ethyl acetate. Packing of the Preyssler-type molecules was observed by high-resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM)

Encapsulation of Two Potassium Cations in Preyssler-Type Phosphotungstates: Preparation, Structural Characterization, Thermal Stability, Activity as an Acid Catalyst, and HAADF-STEM Images

Dipotassium cation (K⁺)-encapsulated Preyssler-type phosphotungstate, [P₅W₃₀O₁₁₀K₂]^13‑, was prepared by heating monobismuth (Bi³⁺)-encapsulated Preyssler-type phosphotungstate, [P₅W₃₀O₁₁₀Bi­(H₂O)]^12‑, in acetate buffer in the presence of an excess amount of potassium cations. Characterization of the isolated potassium salt, K₁₃[P₅W₃₀O₁₁₀K₂] (<b>1a</b>), and its acid form, H₁₃[P₅W₃₀O₁₁₀K₂] (<b>1b</b>), by single crystal X-ray structure analysis, ³¹P and ¹⁸³W nuclear magnetic resonance (NMR), Fourier transform infrared (FT-IR) spectroscopy, cyclic voltammetry (CV), high-resolution electrospray ionization mass spectroscopy (HR-ESI-MS), and elemental analysis revealed that two potassium cations are encapsulated in the Preyssler-type phosphotungstate molecule with formal <i>D</i>_5<i>h</i> symmetry, which is the first example of a Preyssler-type compound with two encapsulated cations. Incorporation of two potassium cations enhances the thermal stability of the potassium salt, and the acid form shows catalytic activity for hydration of ethyl acetate. Packing of the Preyssler-type molecules was observed by high-resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM)

Encapsulation of Two Potassium Cations in Preyssler-Type Phosphotungstates: Preparation, Structural Characterization, Thermal Stability, Activity as an Acid Catalyst, and HAADF-STEM Images

Dipotassium cation (K⁺)-encapsulated Preyssler-type phosphotungstate, [P₅W₃₀O₁₁₀K₂]^13‑, was prepared by heating monobismuth (Bi³⁺)-encapsulated Preyssler-type phosphotungstate, [P₅W₃₀O₁₁₀Bi­(H₂O)]^12‑, in acetate buffer in the presence of an excess amount of potassium cations. Characterization of the isolated potassium salt, K₁₃[P₅W₃₀O₁₁₀K₂] (<b>1a</b>), and its acid form, H₁₃[P₅W₃₀O₁₁₀K₂] (<b>1b</b>), by single crystal X-ray structure analysis, ³¹P and ¹⁸³W nuclear magnetic resonance (NMR), Fourier transform infrared (FT-IR) spectroscopy, cyclic voltammetry (CV), high-resolution electrospray ionization mass spectroscopy (HR-ESI-MS), and elemental analysis revealed that two potassium cations are encapsulated in the Preyssler-type phosphotungstate molecule with formal <i>D</i>_5<i>h</i> symmetry, which is the first example of a Preyssler-type compound with two encapsulated cations. Incorporation of two potassium cations enhances the thermal stability of the potassium salt, and the acid form shows catalytic activity for hydration of ethyl acetate. Packing of the Preyssler-type molecules was observed by high-resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM)

Hepatic rRNA Transcription Regulates High-Fat-Diet-Induced Obesity

Ribosome biosynthesis is a major intracellular energy-consuming process. We previously identified a nucleolar factor, nucleomethylin (NML), which regulates intracellular energy consumption by limiting rRNA transcription. Here, we show that, in livers of obese mice, the recruitment of NML to rRNA gene loci is increased to repress rRNA transcription. To clarify the relationship between obesity and rRNA transcription, we generated NML-null (NML-KO) mice. NML-KO mice show elevated rRNA level, reduced ATP concentration, and reduced lipid accumulation in the liver. Furthermore, in high-fat-diet (HFD)-fed NML-KO mice, hepatic rRNA levels are not decreased. Both weight gain and fat accumulation in HFD-fed NML-KO mice are significantly lower than those in HFD-fed wild-type mice. These findings indicate that rRNA transcriptional activation promotes hepatic energy consumption, which alters hepatic lipid metabolism. Namely, hepatic rRNA transcriptional repression by HFD feeding is essential for energy storage