Ono Kenji
Department of Neurotoxicology, Graduate School of Medical Sciences and Medical School, Nagoya City University, Nagoya 467-8601, Japan.
Department of Brain Function, Division of Stress Adaptation and Protection, Research Institute of Environmental Medicine, Nagoya University, Nagoya 464-8601, Japan.
Int J Mol Sci. 2024 Dec 18;25(24):13534. doi: 10.3390/ijms252413534.
Signal peptides (SPs), peptide sequences located at the N-terminus of newly synthesized proteins, are primarily known for their role in targeting proteins to the endoplasmic reticulum (ER). It has traditionally been assumed that cleaved SPs are rapidly degraded and digested near the ER. However, recent evidence has demonstrated that cleaved SP fragments can be detected in extracellular fluids such as blood flow, where they exhibit bioactivity. In addition, SP fragments are delivered to extracellular fluids via extracellular vesicles such as exosomes and microvesicles, which are important mediators of intercellular communication. These findings suggest that SPs and their fragments may have physiological roles beyond their classical function. This review aims to provide a comprehensive overview of these novel roles and offer new insights into the potential functions of SPs and their fragments in post-translational regulation and intercellular communication.
信号肽（SPs）是位于新合成蛋白质N端的肽序列，主要因其在将蛋白质靶向内质网（ER）中的作用而闻名。传统上认为，被切割的信号肽会在内质网附近迅速降解和消化。然而，最近的证据表明，在诸如血流等细胞外液中可以检测到被切割的信号肽片段，它们在其中表现出生物活性。此外，信号肽片段通过细胞外囊泡（如外泌体和微囊泡）被递送到细胞外液中，这些囊泡是细胞间通讯的重要介质。这些发现表明，信号肽及其片段可能具有超越其经典功能的生理作用。本综述旨在全面概述这些新作用，并为信号肽及其片段在翻译后调控和细胞间通讯中的潜在功能提供新的见解。
