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Updated: Jun 8, 2026

In Situ Detection of Ribonucleoprotein Complex Assembly in the C. elegans Germline using Proximity Ligation Assay
Published on: May 5, 2020
Novel mutations of the LolCDE complex causing outer membrane localization of lipoproteins despite their inner
Chihiro Sakamoto1, Rika Satou, Hajime Tokuda
1Institute of Molecular and Cellular Biosciences, University of Tokyo, Tokyo 113-0032, Japan.
Abstract:
In Gram-negative bacteria, lipoproteins are targeted to either the inner or outer membrane depending on their sorting signals. An ABC transporter LolCDE complex in Escherichia coli releases outer membrane-specific lipoproteins. Inner membrane-specific lipoproteins remain in the inner membrane because they each have a LolCDE-avoidance signal and therefore are not released by LolCDE. Only the LolC(A40P) mutation was previously found to cause outer membrane localization of lipoproteins despite their inner membrane-retention signals. Here, we isolated several new LolCDE mutants that cause outer membrane localization of lipoproteins possessing LolCDE-avoidance signals. Mutations were found in all three subunits of LolCDE, including the cytoplasmic ATPase subunit LolD. However, the extent of outer membrane sorting of inner membrane-specific lipoproteins differed depending on the mutation. Based on these observations, the molecular events underlying the recognition of lipoproteins by the LolCDE complex are discussed.
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