Biomolecular condensation of ERC1 recruits ATG8 and NBR1 to drive autophagosome formation for plant heat tolerance.

Macroautophagy (hereafter autophagy) is essential for cells to respond to nutrient stress by delivering cytosolic contents to vacuoles for degradation via the formation of a multi-layer vesicle named autophagosome. A set of autophagy-related (ATG) regulators are recruited to the phagophore assembly site for the initiation of phagophore, as well as its expansion and closure and subsequent delivery into the vacuole. However, it remains elusive that how the phagophore assembly is regulated under different stress conditions.

Microscopy Analysis of Autophagosomal Structures in Plant Cells.

Macroautophagy, hereafter autophagy, plays a crucial role in the degradation of harmful or unwanted cellular components through a double-membrane autophagosome. Upon autophagosome fusion with the vacuole, the degraded materials are subsequently recycled to generate macromolecules, contributing to cellular homeostasis, metabolism, and stress tolerance in plants. A hallmark during autophagy is the formation of isolation membrane structure named as phagophore, which undergoes multiple steps to become as a complete double-membrane autophagosome.

Protein degrons and degradation: Exploring substrate recognition and pathway selection in plants.

Proteome composition is dynamic and influenced by many internal and external cues, including developmental signals, light availability, or environmental stresses. Protein degradation, in synergy with protein biosynthesis, allows cells to respond to various stimuli and adapt by reshaping the proteome. Protein degradation mediates the final and irreversible disassembly of proteins, which is important for protein quality control and to eliminate misfolded or damaged proteins, as well as entire organelles.

Subscaling of a cytosolic RNA binding protein governs cell size homeostasis in the multiple fission alga Chlamydomonas.

Coordination of growth and division in eukaryotic cells is essential for populations of proliferating cells to maintain size homeostasis, but the underlying mechanisms that govern cell size have only been investigated in a few taxa. The green alga Chlamydomonas reinhardtii (Chlamydomonas) proliferates using a multiple fission cell cycle that involves a long G1 phase followed by a rapid series of successive S and M phases (S/M) that produces 2n daughter cells. Two control points show cell-size dependence: the Commitment control point in mid-G1 phase requires the attainment of a minimum size to enable at least one mitotic division during S/M, and the S/M control point where mother cell size governs cell division number (n), ensuring that daughter distributions are uniform.

A century journey of organelles research in the plant endomembrane system.

We are entering an exciting century in the study of the plant organelles in the endomembrane system. Over the past century, especially within the past 50 years, tremendous advancements have been made in the complex plant cell to generate a much clearer and informative picture of plant organelles, including the molecular/morphological features, dynamic/spatial behavior, and physiological functions. Importantly, all these discoveries and achievements in the identification and characterization of organelles in the endomembrane system would not have been possible without: (1) the innovations and timely applications of various state-of-art cell biology tools and technologies for organelle biology research; (2) the continuous efforts in developing and characterizing new organelle markers by the plant biology community; and (3) the landmark studies on the identification and characterization of the elusive organelles.

Indole Diterpene Derivatives from the GZWMJZ-288, an Endophytic Fungus from .

A new indole diterpene, 26-dihydroxyaflavininyl acetate (), along with five known analogs (-) were isolated from the liquid fermentation of GZWMJZ-288, an endophyte from . The structures of these compounds were identified through NMR, MS, chemical reaction, and X-ray diffraction experiments. Enzyme inhibition activity screening found that compounds , , and have a good binding affinity with NPC1L1, among which compound exhibited a stronger binding ability than ezetimibe at a concentration of 10 µM.

Recent advances in plant endomembrane research and new microscopical techniques.

The endomembrane system consists of various membrane-bound organelles including the endoplasmic reticulum (ER), Golgi apparatus, trans-Golgi network (TGN), endosomes, and the lysosome/vacuole. Membrane trafficking between distinct compartments is mainly achieved by vesicular transport. As the endomembrane compartments and the machineries regulating the membrane trafficking are largely conserved across all eukaryotes, our current knowledge on organelle biogenesis and endomembrane trafficking in plants has mainly been shaped by corresponding studies in mammals and yeast.

A positive feedback regulation of SnRK1 signaling by autophagy in plants.

SnRK1, an evolutionarily conserved heterotrimeric kinase complex that acts as a key metabolic sensor in maintaining energy homeostasis in plants, is an important upstream activator of autophagy that serves as a cellular degradation mechanism for the healthy growth of plants. However, whether and how the autophagy pathway is involved in regulating SnRK1 activity remains unknown. In this study, we identified a clade of plant-specific and mitochondria-localized FCS-like zinc finger (FLZ) proteins as currently unknown ATG8-interacting partners that actively inhibit SnRK1 signaling by repressing the T-loop phosphorylation of the catalytic α subunits of SnRK1, thereby negatively modulating autophagy and plant tolerance to energy deprivation caused by long-term carbon starvation.

ABI5-FLZ13 module transcriptionally represses growth-related genes to delay seed germination in response to ABA.

The bZIP transcription factor ABSCISIC ACID INSENSITIVE5 (ABI5) is a master regulator of seed germination and post-germinative growth in response to abscisic acid (ABA), but the detailed molecular mechanism by which it represses plant growth remains unclear. In this study, we used proximity labeling to map the neighboring proteome of ABI5 and identified FCS-LIKE ZINC FINGER PROTEIN 13 (FLZ13) as a novel ABI5 interaction partner. Phenotypic analysis of flz13 mutants and FLZ13-overexpressing lines demonstrated that FLZ13 acts as a positive regulator of ABA signaling.

Arabidopsis AUTOPHAGY-RELATED2 is essential for ATG18a and ATG9 trafficking during autophagosome closure.

As a fundamental metabolic pathway, autophagy plays important roles in plant growth and development, particularly under stress conditions. A set of autophagy-related (ATG) proteins is recruited for the formation of a double-membrane autophagosome. Among them, the essential roles of ATG2, ATG18, and ATG9 have been well established in plant autophagy via genetic analysis; however, the underlying molecular mechanism for ATG2 in plant autophagosome formation remains poorly understood.

A non-canonical role of ATG8 in Golgi recovery from heat stress in plants.

Above-optimal growth temperatures, usually referred to as heat stress (HS), pose a challenge to organisms' survival as they interfere with essential physiological functions and disrupt cellular organization. Previous studies have elucidated the complex transcriptional regulatory networks involved in plant HS responses, but the mechanisms of organellar remodelling and homeostasis during plant HS adaptations remain elusive. Here we report a non-canonical function of ATG8 in regulating the restoration of plant Golgi damaged by HS.

A plant-unique protein BLISTER coordinates with core retromer to modulate endosomal sorting of plasma membrane and vacuolar proteins.

The retromer is a heteromeric protein complex that localizes to endosomal membranes and drives the formation of endosomal tubules that recycle membrane protein cargoes. In plants, the retromer plays essential and canonical functions in regulating the transport of vacuolar storage proteins and the recycle of endocytosed plasma membrane proteins (PM); however, the mechanisms underlying the regulation of assembly, protein stability, and membrane recruitment of the plant retromer complex remain to be elucidated. In this study, we identify a plant-unique endosomal regulator termed BLISTER (BLI), which colocalizes and associates with the retromer complex by interacting with the retromer core subunits VPS35 and VPS29.

VAMP724 and VAMP726 are involved in autophagosome formation in .

Macroautophagy/autophagy, an evolutionarily conserved degradative process essential for cell homeostasis and development in eukaryotes, involves autophagosome formation and fusion with a lysosome/vacuole. The soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins play important roles in regulating autophagy in mammals and yeast, but relatively little is known about SNARE function in plant autophagy. Here we identified and characterized two SNAREs, AT4G15780/VAMP724 and AT1G04760/VAMP726, involved in plant autophagy.

Cu-MOF@Pt 3D nanocomposites prepared by one-step wrapping method with peroxidase-like activity for colorimetric detection of glucose.

As an alternative to natural enzymes, artificial enzymes based on nanomaterials have attracted a lot of attention owing to their outstanding catalytic activity and high stability as well as low cost. Cu-MOF loaded with platinum nanoparticles (labeled Cu-MOF@Pt) was prepared by simple one-step wrapping method using platinum nanoparticles, copper nitrate trihydrate and 1,3,5-tricarboxybenzene. It was confirmed that Cu-MOF@Pt exhibits peroxidase-like activity, which can quickly catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) and produce blue oxidized TMB (oxTMB) in the presence of hydrogen peroxide (HO).

MLKs kinases phosphorylate the ESCRT component FREE1 to suppress abscisic acid sensitivity of seedling establishment.

The FYVE domain protein required for endosomal sorting 1 (FREE1), which was previously identified as a plant-specific component of the endosomal sorting complex required for transport machinery, plays an essential role in endosomal trafficking. Moreover, FREE1 also functions as an important negative regulator in abscisic acid (ABA) signalling. Multiple phosphorylations and ubiquitination sites have been identified in FREE1, hence unveiling the factors involved in posttranslational regulation of FREE1 is critical for comprehensively understanding FREE1-related regulatory networks during plant growth.

Shedding Light on the Role of Phosphorylation in Plant Autophagy.

Autophagy is a highly conserved quality control process that maintains cellular health by eliminating deleterious cargoes. Compared with the extensive studies in yeast and mammalian models, the molecular details and significance of post-translational modifications (PTMs) in the autophagy process in plants remain less well defined. In this review, we discuss recent progress in our understanding of phosphorylation, one of the most extensively studied PTMs, in the regulation of autophagosome biogenesis and autophagic degradation in plants.

An Update on Coat Protein Complexes for Vesicle Formation in Plant Post-Golgi Trafficking.

Endomembrane trafficking is an evolutionarily conserved process for all eukaryotic organisms. It is a fundamental and essential process for the transportation of proteins, lipids, or cellular metabolites. The aforementioned cellular components are sorted across multiple membrane-bounded organelles.

Mechanistic insights into an atypical interaction between ATG8 and SH3P2 in .

In selective macroautophagy/autophagy, cargo receptors are recruited to the forming autophagosome by interacting with Atg8 (autophagy-related 8)-family proteins and facilitate the selective sequestration of specific cargoes for autophagic degradation. In addition, Atg8 interacts with a number of adaptors essential for autophagosome biogenesis, including ATG and non-ATG proteins. The majority of these adaptors and receptors are characterized by an Atg8-family interacting motif (AIM) for binding to Atg8.

AS1 expression in prostate cancer and its effects on proliferation and invasion of prostate cancer cells.

This paper aimed at investigating AS1 expression in prostate cancer (PCa) and its effects on the proliferation and invasion of prostate cancer cells (PCCs). The prostate tissues and the matched adjacent normal prostate tissues excised and preserved during radical prostatectomy in our hospital were collected. The LncRNA NCK1-AS1 expression was detected.