HERC3 facilitates ERAD of select membrane proteins by recognizing membrane-spanning domains.

Aberrant proteins located in the endoplasmic reticulum (ER) undergo rapid ubiquitination by multiple ubiquitin (Ub) E3 ligases and are retrotranslocated to the cytosol as part of the ER-associated degradation (ERAD). Despite several ERAD branches involving different Ub E3 ligases, the molecular machinery responsible for these ERAD branches in mammalian cells remains not fully understood. Through a series of multiplex knockdown/knockout experiments with real-time kinetic measurements, we demonstrate that HERC3 operates independently of the ER-embedded ubiquitin ligases RNF5 and RNF185 (RNF5/185) to mediate the retrotranslocation and ERAD of misfolded CFTR.

Screening of factors inducing alveolar type 1 epithelial cells using human pluripotent stem cells.

Alveolar type 2 (AT2) epithelial cells are tissue stem cells capable of differentiating into alveolar type 1 (AT1) cells for injury repair and maintenance of lung homeostasis. However, the factors involved in human AT2-to-AT1 cell differentiation are not fully understood. Here, we established SFTPC and AGER dual-reporter induced pluripotent stem cells (iPSCs), which detected AT2-to-AT1 cell differentiation with high sensitivity and identified factors inducing AT1 cell differentiation from AT2 and their progenitor cells.

Conformational relaxation of sigma-conjugated polymer radical anion on picosecond scale.

We report the conformational relaxation of poly[bis(p-n-butylphenyl)silane] (PBPS) radical anion measured by near-ultraviolet-enhanced picosecond pulse radiolysis in tetrahydrofuran solutions. The peak shift and increase in optical density of the transient photoabsorption spectra were investigated by kinetic analysis including reactions of PBPS with solvated/presolvated electrons, peak extraction protocol, and diffusion theory, demonstrating the correspondence in the rate constant (5+/-1x10(2) ps) between the peak shift and increase in oscillator strength. The results were examined by density functional theory and molecular dynamics simulations, where the modeled oligosilane radical anion shows more planner conformation relative to its neutral state and a relaxation time of 8 ps.

Reactivity between biphenyl and precursor of solvated electrons in tetrahydrofuran measured by picosecond pulse radiolysis in near-ultraviolet, visible, and infrared.

The initial decrease of solvated electrons in tetrahydrofuran (THF) upon addition of biphenyl was investigated by picosecond pulse radiolysis. Transient absorption spectra derived from the biphenyl radical anion (centered at 408 and 655 nm) and solvated electrons of THF (infrared) were successfully measured in the wavelength region from 400 to 900 nm by the extension of a femtosecond continuum probe light to near-ultraviolet using a second harmonic generation of Ti:sapphire laser and a CaF2 plate. From the analysis of kinetic traces at 1300 nm considering the overlap of primary solvated electrons and partial biphenyl radical anion, C37, which is defined by the solute concentration to reduce the initial yield of solvated electrons to 1/e, was found to be 87 +/- 3 mM.