Positively charged cytoplasmic residues in corin prevent signal peptidase cleavage and endoplasmic reticulum retention
Abstract Positively charged residues are commonly located near the cytoplasm-membrane interface, which is known as the positive-inside rule in membrane topology. The mechanism underlying the function of these charged residues remains poorly understood. Herein, we studied the function of cytoplasmic...
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| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2025-01-01
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| Series: | Communications Biology |
| Online Access: | https://doi.org/10.1038/s42003-025-07545-7 |
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| Summary: | Abstract Positively charged residues are commonly located near the cytoplasm-membrane interface, which is known as the positive-inside rule in membrane topology. The mechanism underlying the function of these charged residues remains poorly understood. Herein, we studied the function of cytoplasmic residues in corin, a type II transmembrane serine protease in cardiovascular biology. We found that the positively charged residue at the cytoplasm-membrane interface of corin was not a primary determinant in membrane topology but probably served as a charge-repulsion mechanism in the endoplasmic reticulum (ER) to prevent interactions with proteins in the ER, including the signal peptidase. Substitution of the positively charged residue with a neutral or acidic residue resulted in corin secretion likely due to signal peptidase cleavage. In signal peptidase-deficient cells, the mutant corin proteins were not secreted but retained in the ER. Similar results were found in the low-density lipoprotein receptor and matriptase-2 that have positively charged residues at and near the cytoplasm-membrane interface. These results provide important insights into the role of the positively charged cytoplasmic residues in mammalian single-pass transmembrane proteins. |
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| ISSN: | 2399-3642 |