Beige fat activation involves a fuel switch to fatty acid oxidation following chronic cold adaptation. Mitochondrial acyl-CoA synthetase long-chain family member 1 (ACSL1) localizes in the mitochondria and plays a key role in fatty acid oxidation; however, the regulatory mechanism of the subcellular localization remains poorly understood. Here, we identify an endosomal trafficking component sortilin (encoded by Sort1) in adipose tissues that shows dynamic expression during beige fat activation and facilitates the translocation of ACSL1 from the mitochondria to the endolysosomal pathway for degradation. Depletion of sortilin in adipocytes results in an increase of mitochondrial ACSL1 and the activation of AMPK/PGC1α signaling, thereby activating beige fat and preventing high-fat diet (HFD)-induced obesity and insulin resistance. Collectively, our findings indicate that sortilin controls adipose tissue fatty acid oxidation by substrate fuel selection during beige fat activation and provides a potential targeted approach for the treatment of metabolic diseases.

Most bacteria will use their toxins to interact with the host cell, causing damage to the cell and then escaping from it. When bacteria enter the cell, they will be transported via the endosomal pathway. Rab GTPases are involved in bacterial transport as major components of endosomes that bind to their downstream effector proteins. The bacteria manipulate some Rab GTPases, escape the cell, and get to survive. In this review, we will focus on summarizing the many processes of how bacteria manipulate Rab GTPases to control their escape.

NLRP3 inflammasome activation, essential for cytokine secretion and pyroptosis in response to diverse stimuli, is closely associated with various diseases. Upon stimulation, NLRP3 undergoes subcellular membrane trafficking and conformational rearrangements, preparing itself for inflammasome assembly at the microtubule-organizing center (MTOC). Here, we elucidate an orchestrated mechanism underlying these ordered processes using human and murine cells. Specifically, NLRP3 undergoes palmitoylation at two sites by palmitoyl transferase zDHHC1, facilitating its trafficking between subcellular membranes, including the mitochondria, trans-Golgi network (TGN), and endosome. This dynamic trafficking culminates in the localization of NLRP3 to the MTOC, where LATS1/2, pre-recruited to MTOC during priming, phosphorylates NLRP3 to further facilitate its interaction with NIMA-related kinase 7 (NEK7), ultimately leading to full NLRP3 activation. Consistently, Zdhhc1-deficiency mitigated LPS-induced inflammation and conferred protection against mortality in mice. Altogether, our findings provide valuable insights into the regulation of NLRP3 membrane trafficking and inflammasome activation, governed by palmitoylation and phosphorylation events.

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Epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase receptor and a member of the ErbB receptor family. As a significant cancer driver, EGFR undergoes mutations such as gene amplification or overexpression in a wide range of malignant tumors and is closely associated with tumorigenesis. This review examines the aberrant expression of EGFR in several common cancers and summarizes the current therapeutic strategies developed for this receptor. Additionally, this review compares the differences in EGFR activation, internalization, endocytosis, and sorting in normal and cancer cells, and highlights some regulatory factors that influence its trafficking process.Kindly check and confirm the edit made in the title.Yes, correctAs per journal instructions structured abstract is mandatory kindly provideThe abstract format does not apply to Review articles.

Ciliary beat and intraflagellar transport depend on dynein and kinesin motors. The kinesin-9 family members Kif6 and Kif9 are implicated in motile cilia motilities across protists and mammals. How they function and whether they act redundantly, however, remain unclear. Here, we show that Kif6 and Kif9 play distinct roles in mammals. Kif6 forms puncta that move bidirectionally along axonemes, whereas Kif9 appears to oscillate regionally on the ciliary central apparatus. Consistently, only Kif6 displays microtubule-based motor activity in vitro, and its ciliary localization requires its ATPase activity. Kif6 deficiency in mice disrupts coordinated ciliary beat across ependymal tissues and impairs cerebrospinal fluid flow, resulting in severe hydrocephalus and high mortality. Kif9 deficiency causes mild hydrocephalus without obviously affecting the ciliary beat or the lifespan. Kif6-/- and Kif9-/- males are infertile but exhibit oligozoospermia with poor sperm motility and defective forward motion of sperms, respectively. These results suggest Kif6 as a motor for cargo transport and Kif9 as a central apparatus regulator.

The endomembrane system in plants is composed of interconnected membrane organelles that contribute to intracellular structure and function. These organelles include the endoplasmic reticulum (ER), Golgi apparatus, vacuole, trans-Golgi network, and prevacuolar compartment or multivesicular body. Through vesicle-mediated transport, secreted proteins are synthesized in the ER and subsequently transported along the secretory pathway to the vacuole or outside of cells to fulfill specialized functions. Genetic screening is a crucial method for studying plant protein secretion. It entails identifying phenotypic differences resulting from genetic mutations, such as ethyl methanesulfonate, T-DNA insertion, and RNAi, to investigate gene function and discover mutants with specific traits or gene functions. Significant progress has been achieved in the study of plant protein secretion through genetic screening. In this protocol, we provide a step-by-step guide to studying the protein secretion pathway using a genetic screen approach. We use the example of the free 1 suppressor of Arabidopsis thaliana and oil body mutants of Marchantia polymorpha. Additionally, we offer an overview of genetic screening and briefly summarize the emerging technologies in the field of protein secretion research.

Vesicle trafficking is an essential cellular process conserved in eukaryotes to precisely transport proteins to their destinations. The plant endomembrane system plays a pivotal role in orchestrating this vesicle-mediated protein transport process, making its study essential for a comprehensive understanding of plant growth and development. Pharmaceutical analysis proves highly useful in investigating the plant endomembrane system. To facilitate further studies in this area, we present a summary of several commonly used chemical inhibitors in this chapter, providing a practical resource for researchers interested in the plant endomembrane system.

Time-lapse imaging of the subcellular localization and dynamic behavior of proteins is critical to understand their biological functions in cells. With the advent of various methodologies and computational tools, the precise tracking and quantification of protein spatiotemporal dynamics have become feasible. Kymograph analysis, in particular, has been extensively adopted for the quantitative assessment of proteins, vesicles, and organelle movements. However, conventional kymograph analysis, which is based on a single linear trajectory, may not comprehensively capture the complexity of proteins that alter their course during intracellular transport and activity. In this chapter, we introduced an advanced protocol for whole-cell kymograph analysis that allows for three-dimensional (3D) tracking of protein dynamics. This method was validated through the analysis of tip-focused endocytosis and exocytosis processes in growing tobacco pollen tubes by employing both the advanced whole-cell and classical kymograph methods. In addition, we enhanced this method by integrating pseudo-colored kymographs that enables the direct visualization of changes in protein fluorescence intensity with fluorescence recovery after photobleaching to advance our understanding of protein localization and dynamics. This comprehensive method offers a novel insight into the intricate dynamics of protein activity within the cellular context.

In the endomembrane system, multivesicular bodies (MVBs) play a crucial role in sorting ubiquitinated membrane proteins into intraluminal vesicles for degradation upon fusion with vacuoles or lysosomes. This process involves regulations by multiprotein complexes, including endosomal sorting complex required for transport (ESCRT) I-III, and accessory proteins. Although many organellar proteomes have been identified in plant cells, the information of specific proteomes associated with regulators engaged in MVB biogenesis remains limited. Here, using the ESCRT component FREE1 as an example, we describe a method to identify neighboring proteins of endosomal regulators by using an approach of TurboID-based proximity labeling.