EPI64 is a TBC domain-containing protein that binds the PDZ domains of EBP50, which binds ezrin, a major actin-binding protein of microvilli. High-resolution light microscopy revealed that ezrin and EBP50 localize exclusively to the membrane-surrounded region of microvilli, whereas EPI64 localizes to variable regions in the structures. Overexpressing EPI64 results in its and EBP50's relocalization to the base of microvilli, including to the actin rootlet devoid of ezrin or plasma membrane. Uncoupling EPI64's binding to EBP50, expression of any construct mislocalizing its TBC domain, or knock down of EBP50 results in loss of microvilli. The TBC domain of EPI64 binds directly to Arf6-GTP. Overexpressing the TBC domain increases Arf6-GTP levels, and expressing dominant-active Arf6 results in microvillar loss. These data reveal that microvilli have distinct cytoskeletal subdomains and that EPI64 regulates microvillar structure.
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http://dx.doi.org/10.1083/jcb.200604046 | DOI Listing |
Nat Commun
January 2025
Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, 78712, USA.
Type II CRISPR endonucleases are widely used programmable genome editing tools. Recently, CRISPR-Cas systems with highly compact nucleases have been discovered, including Cas9d (a type II-D nuclease). Here, we report the cryo-EM structures of a Cas9d nuclease (747 amino acids in length) in multiple functional states, revealing a stepwise process of DNA targeting involving a conformational switch in a REC2 domain insertion.
View Article and Find Full Text PDFClin Kidney J
December 2024
Division of Nephrology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
We report the case of a 49-year-old Chinese woman with nephrotic syndrome, characterized by normal kidney function but poor response to hormonal and immunosuppressive therapy, indicative of steroid-resistant nephrotic syndrome. Through renal biopsy, the patient was diagnosed as havingfocal segmental glomerulosclerosis (perihilar type), and subsequent whole-exome sequencing identified a pathogenic frameshift variant concerning the TBC domain of the gene. This patient represents the first late-onset Chinese female who was found to carry a novel, pathogenic variant in the gene .
View Article and Find Full Text PDFSci Rep
October 2024
Pattern Recognition Lab, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058, Erlangen, Germany.
Diffusion-weighted imaging (DWI) is a magnetic resonance imaging (MRI) technique that provides information about the Brownian motion of water molecules within biological tissues. DWI plays a crucial role in stroke imaging and oncology, but its diagnostic value can be compromised by the inherently low signal-to-noise ratio (SNR). Conventional supervised deep learning-based denoising techniques encounter challenges in this domain as they necessitate noise-free target images for training.
View Article and Find Full Text PDFJ Mol Biol
November 2024
College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, Sichuan 610068, China; State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China; School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 1 Sub-lane Xiangshan, Hangzhou 310024, China. Electronic address:
Optineurin (OPTN), a multifunctional adaptor protein in mammals, plays critical roles in many cellular processes, such as vesicular trafficking and autophagy. Notably, mutations in optineurin are directly associated with many human diseases, such as amyotrophic lateral sclerosis (ALS). OPTN can specifically recognize Rab8a and the GTPase-activating protein TBC1D17, and facilitate the inactivation of Rab8a mediated by TBC1D17, but with poorly understood mechanism.
View Article and Find Full Text PDFAutophagy
November 2024
International Institutes of Medicine, The Fourth Affiliated Hospital of Zhejiang University School of Medicine, Yiwu, China.
Macroautophagic/autophagic and endocytic pathways play essential roles in maintaining homeostasis at different levels. It remains poorly understood how both pathways are coordinated and fine-tuned for proper lysosomal degradation of diverse cargoes. We and others recently identified a Golgi-resident RAB GTPase, RAB2A, as a positive regulator that controls both autophagic and endocytic pathways.
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