Liquid– liquid phase-separated biomolecular condensates, liquid beads play a crucial function in numerous biological procedures, such as gene expression, protein translation, tension action, and protein destruction, by integrating a range of RNA and customer proteins into their interior depending upon the intracellular context. *
Autophagy is associated with the destruction of a number of cytoplasmic liquid beads, consisting of tension granules and P bodies, and flaws in this procedure are believed to trigger shift of these beads to the strong stage, leading to the advancement of intractable illness such as neurodegenerative conditions and cancer. *
Of the beads that have a distinct biological function and are deteriorated by autophagy, p62 bodies (likewise called p62 beads) are liquid beads formed by liquid– liquid stage separation (LLPS) of p62 and its binding partners, ubiquitinated proteins. *
p62 bodies are associated with the guideline of intracellular proteostasis through their own autophagic destruction, and likewise add to the guideline of the significant stress-response system by sequestration of a customer protein, kelch-like ECH-associated protein 1 (KEAP1). *
NRF2 is a transcription aspect accountable for antioxidant tension actions that is normally managed in a redox-dependent way. p62 bodies formed by liquid– liquid stage separation consist of Ser349-phosphorylated p62, which takes part in the redox-independent activation of NRF2. *
Nevertheless, the regulative system and physiological significance of p62 phosphorylation stay uncertain. *
In the short article “ Phosphorylation of phase-separated p62 bodies by ULK1 triggers a redox-independent tension action” Ryo Ikeda, Daisuke Noshiro, Hideaki Morishita, Shuhei Takada, Shun Kageyama, Yuko Fujioka, Tomoko Funakoshi, Satoko Komatsu-Hirota, Ritsuko Arai, Elena Ryzhii, Manabu Abe, Tomoaki Koga, Hozumi Motohashi, Mitsuyoshi Nakao, Kenji Sakimura, Arata Horii, Satoshi Waguri, Yoshinobu Ichimura, Nobuo N Noda and Masaaki Komatsu recognize ULK1 as a kinase accountable for the phosphorylation of p62. *
ULK1 colocalizes with p62 bodies, straight communicating with p62. ULK1-dependent phosphorylation of p62 enables KEAP1 to be kept within p62 bodies, hence triggering NRF2. p62S351E/+ mice are phosphomimetic knock-in mice in which Ser351, representing human Ser349, is changed by Glu. *
These mice, however not their phosphodefective p62S351A/S351A equivalents, display NRF2 hyperactivation and development retardation. This retardation is brought on by poor nutrition and dehydration due to blockage of the esophagus and forestomach secondary to hyperkeratosis, a phenotype likewise observed in systemic Keap1-knockout mice. *
The authors’ outcomes broaden our understanding of the physiological value of the redox-independent NRF2 activation path and offer brand-new insights into the function of stage separation in this procedure. *
To clarify whether the ULK1 kinase itself has an impact on the physical homes and physiological function of p62 bodies, Ryo Ikeda et al. very first studied the physical interaction of p62 with ULK1 or its yeast homolog Atg1 utilizing high-speed atomic force microscopy (HS-AFM). *
HS-AFM of p62 (268– 440 aa) pictured a homodimeric structure, moderated by the dimerization of the UBA domain, that formed a hammer-shaped structure with IDRs twisted around each other. *
HS-AFM images were obtained in tapping mode utilizing a sample-scanning HS-AFM instrument. NanoWorld Ultra-Short Cantilevers of the USC-F1.2- k0.15 AFM probe type were utilized. (~ 7 μm long, ~ 2 μm broad, and ~ 0.08 μm close electron beam-deposited (EBD) ideas (pointer radius << 10 nm). Their resonant frequency and spring consistent were 1.2 MHz in air and 0.15 N/m, respectively. *
![Figure EV1 from âPhosphorylation of phase-separated p62 bodies by ULK1 activates a redox-independent stress responseâ by Ryo Ikeda et al.:HS-AFM observation of SNAP-ULK1 and p62 (268â440âaa), and complex of SNAP-Atg1/p62 (268â440âaa) A, B. Successive HS-AFM images of SNAP-ULK1 (A) and p62_268â440 (B). Height scale: 0â4.4ânm (A), 0â3.4ânm (B); scale bar: 20ânm (A, B). C. Successive HS-AFM images of p62_268â440 with SNAP-Atg1. Height scale: 0â3.6ânm; scale bar: 30ânm. D. Schematics showing the molecular characteristics determined by HS-AFM. Gray spheres, globular domains consisting of N-terminal KD and C-terminal MIT of Atg1; pink spheres, globular domains consisting of C-terminal UBA domain of p62; blue thick solid lines, IDRs. NanoWorld Ultra-Short Cantilevers of the USC-F1.2-k0.15 AFM probe type were used.](https://dhipgo7nn2tea.cloudfront.net/wp-content/uploads/2023/08/02151821/Fig-EV1-from-Phosphorylation-of-phase-separated-p62-bodies-by-ULK1-activates-a-redox-independent-stress-response-by-Ryo-Ikeda-et-al-2023-NanoWorld-USC-F1.2-k0.15-AFM-probe.jpg)
HS-AFM observation of SNAP-ULK1 and p62 (268– 440 aa), and complex of SNAP-Atg1/ p62 (268– 440 aa)
A, B. Successive HS-AFM pictures of SNAP-ULK1 (A) and p62_268– 440 (B). Height scale: 0– 4.4 nm (A), 0– 3.4 nm (B); scale bar: 20 nm (A, B).
C. Successive HS-AFM pictures of p62_268– 440 with SNAP-Atg1. Height scale: 0– 3.6 nm; scale bar: 30 nm.
D. Schematics revealing the molecular qualities identified by HS-AFM. Gray spheres, globular domains including N-terminal KD and C-terminal MIT of Atg1; pink spheres, globular domains including C-terminal UBA domain of p62; blue thick strong lines, IDRs.
* Ryo Ikeda, Daisuke Noshiro, Hideaki Morishita, Shuhei Takada, Shun Kageyama, Yuko Fujioka, Tomoko Funakoshi, Satoko Komatsu-Hirota, Ritsuko Arai, Elena Ryzhii, Manabu Abe, Tomoaki Koga, Hozumi Motohashi, Mitsuyoshi Nakao, Kenji Sakimura, Arata Horii, Satoshi Waguri, Yoshinobu Ichimura, Nobuo N Noda and Masaaki Komatsu
Phosphorylation of phase-separated p62 bodies by ULK1 triggers a redox-independent tension action
The EMBO Journal (2023 )42: e113349
DOI: https://doi.org/10.15252/embj.2022113349
The short article “ Phosphorylation of phase-separated p62 bodies by ULK1 triggers a redox-independent tension action” by Ryo Ikeda, Daisuke Noshiro, Hideaki Morishita, Shuhei Takada, Shun Kageyama, Yuko Fujioka, Tomoko Funakoshi, Satoko Komatsu-Hirota, Ritsuko Arai, Elena Ryzhii, Manabu Abe, Tomoaki Koga, Hozumi Motohashi, Mitsuyoshi Nakao, Kenji Sakimura, Arata Horii, Satoshi Waguri, Yoshinobu Ichimura, Nobuo N Noda and Masaaki Komatsu is certified under an Imaginative Commons Attribution 4.0 International License, which allows usage, sharing, adjustment, circulation and recreation in any medium or format, as long as you provide suitable credit to the initial author( s) and the source, offer a link to the Creative Commons license, and suggest if modifications were made. The images or other third-party product in this short article are consisted of in the short article’s Creative Commons license, unless shown otherwise in a credit limit to the product. If product is not consisted of in the short article’s Creative Commons license and your planned usage is not allowed by statutory guideline or goes beyond the allowed usage, you will require to acquire approval straight from the copyright holder. To see a copy of this license, go to https://creativecommons.org/licenses/by/4.0/.