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1. Structure and function of H+/K+ pump mutants reveal Na+/K+ pump mechanisms

   https://doi.org/10.1038/s41467-022-32793-0  

   Young, Victoria C.; Nakanishi, Hanayo; Meyer, Dylan J.; Nishizawa, Tomohiro; Oshima, Atsunori; Artigas, Pablo; Abe, Kazuhiro (December 2022, Nature Communications)

   Abstract Ion-transport mechanisms evolve by changing ion-selectivity, such as switching from Na + to H + selectivity in secondary-active transporters or P-type-ATPases. Here we study primary-active transport via P-type ATPases using functional and structural analyses to demonstrate that four simultaneous residue substitutions transform the non-gastric H + /K + pump, a strict H + -dependent electroneutral P-type ATPase, into a bona fide Na + -dependent electrogenic Na + /K + pump. Conversion of a H + -dependent primary-active transporter into a Na + -dependent one provides a prototype for similar studies of ion-transport proteins. Moreover, we solve the structures of the wild-type non-gastric H + /K + pump, a suitable drug target to treat cystic fibrosis, and of its Na + /K + pump-mimicking mutant in two major conformations, providing insight on how Na + binding drives a concerted mechanism leading to Na + /K + pump phosphorylation. 

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2. Modal Decomposition of K- and H-Type Boundary Layer Transition

   https://doi.org/10.2514/6.2024-0495  

   Lin, Cong; Schmidt, Oliver (January 2024, American Institute of Aeronautics and Astronautics)
3. Predicting stellar angular diameters from V, IC, H and K photometry

   https://doi.org/10.1093/mnras/stx2367  

   Adams, Arthur D.; Boyajian, Tabetha S.; von Braun, Kaspar (September 2017, Monthly Notices of the Royal Astronomical Society)
4. Combined analysis of Belle and Belle II data to determine the CKM angle ϕ3 using B+ → D($$ {K}_S^0 $$h+h−)h+ decays

   https://doi.org/10.1007/JHEP02(2022)063  

   Abudinén, F.; Aggarwal, L.; Ahmed, H.; Aihara, H.; Akopov, N.; Al Said, S.; Aloisio, A.; Anh Ky, N.; Asner, D. M.; Atmacan, H.; et al (February 2022, Journal of High Energy Physics)

   A bstract We present a measurement of the Cabibbo-Kobayashi-Maskawa unitarity triangle angle ϕ 3 (also known as γ ) using a model-independent Dalitz plot analysis of B + → D ( $$ {K}_S^0 $$ K S 0 h + h − ) h + , where D is either a D 0 or $$ \overline{D} $$ D ¯ 0 meson and h is either a π or K . This is the first measurement that simultaneously uses Belle and Belle II data, combining samples corresponding to integrated luminosities of 711 fb − 1 and 128 fb − 1 , respectively. All data were accumulated from energy-asymmetric e + e − collisions at a centre-of-mass energy corresponding to the mass of the Υ(4 S ) resonance. We measure ϕ 3 = (78 . 4 ± 11 . 4 ± 0 . 5 ± 1 . 0)°, where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is from the uncertainties on external measurements of the D -decay strong-phase parameters. 

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5. Loss of inner-envelope K+/H+ exchangers impairs plastid rRNA maturation and gene expression

   https://doi.org/10.1093/plcell/koab123  

   DeTar, Rachael Ann; Barahimipour, Rouhollah; Manavski, Nikolay; Schwenkert, Serena; Höhner, Ricarda; Bölter, Bettina; Inaba, Takehito; Meurer, Jörg; Zoschke, Reimo; Kunz, Hans-Henning (May 2021, The Plant Cell)

   Abstract The inner-envelope K+ EFFLUX ANTIPORTERS (KEA) 1 and 2 are critical for chloroplast development, ion homeostasis, and photosynthesis. However, the mechanisms by which changes in ion flux across the envelope affect organelle biogenesis remained elusive. Chloroplast development requires intricate coordination between the nuclear genome and the plastome. Many mutants compromised in plastid gene expression (PGE) display a virescent phenotype, that is delayed greening. The phenotypic appearance of Arabidopsis thaliana kea1 kea2 double mutants fulfills this criterion, yet a link to PGE has not been explored. Here, we show that a simultaneous loss of KEA1 and KEA2 results in maturation defects of the plastid ribosomal RNAs. This may be caused by secondary structure changes of rRNA transcripts and concomitant reduced binding of RNA-processing proteins, which we documented in the presence of skewed ion homeostasis in kea1 kea2. Consequently, protein synthesis and steady-state levels of plastome-encoded proteins remain low in mutants. Disturbance in PGE and other signs of plastid malfunction activate GENOMES UNCOUPLED 1-dependent retrograde signaling in kea1 kea2, resulting in a dramatic downregulation of GOLDEN2-LIKE transcription factors to halt expression of photosynthesis-associated nuclear-encoded genes (PhANGs). PhANG suppression delays the development of fully photosynthesizing kea1 kea2 chloroplasts, probably to avoid progressing photo-oxidative damage. Overall, our results reveal that KEA1/KEA2 function impacts plastid development via effects on RNA-metabolism and PGE. 

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