Evidence of Î³-secretase complex involved in the regulation of intramembrane proteolysis in Entamoeba histolytica.

Makiuchi, Takashi; Saito-Nakano, Yumiko; Nozaki, Tomoyoshi

Makiuchi, Takashi; Saito-Nakano, Yumiko; Nozaki, Tomoyoshi.

Afiliación

Makiuchi T; Department of Infectious Diseases, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa 259-1193, Japan. Electronic address: makky.t.k.s@tokai.ac.jp.
Saito-Nakano Y; Department of Parasitology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
Nozaki T; Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.

Parasitol Int ; 103: 102925, 2024 Dec.

Article en En | MEDLINE | ID: mdl-39048023

ABSTRACT

ABSTRACT

Presenilins (PSNs) are multifunctional membrane proteins involved in signal transduction, lysosomal acidification, and certain physiological processes related to mitochondria. The aspartic protease activity of PSN and the formation of a Î³-secretase complex with other subunits such as nicastrin (NCT) are required for the biological functions. Although PSN is widely conserved in eukaryotes, most studies on PSN were conducted in metazoans. Homologous genes for PSN and NCT (EhPSN and EhNCT, respectively) are encoded in the genome of Entamoeba histolytica, however, their functions remain unknown. In this study, we showed that EhPSN and EhNCT form a complex on the cell membrane, demonstrating that the parasite possesses Î³-secretase. The predicted structure of EhPSN was similar to the human homolog, demonstrated by the crystal structure, and phylogenetic analysis indicated good conservation between EhPSN and human PSN, supporting the premise that EhPSN functions as a subunit of Î³-secretase. By contrast, EhNCT appears to have undergone remarkable structural changes during its evolution. Blue native-polyacrylamide gel electrophoresis combined with western blotting indicated that a 150-kDa single band contains both EhPSN (estimated molecular size 47-kDa) and EhNCT (64-kDa), suggesting that the complex also contains other unknown components or post-translational modifications. Coimmunoprecipitation from amebic lysates also confirmed that EhPSN and EhNCT formed a complex. Indirect immunofluorescence analysis revealed that the complex localized to the plasma membrane. Moreover, EhPSN exhibited protease activity, which was suppressed by a Î³-secretase inhibitor. This is the first report of a Î³-secretase complex in protozoan parasites.

Asunto(s)

Secretasas de la Proteína Precursora del Amiloide; Entamoeba histolytica; Proteolisis; Proteínas Protozoarias; Entamoeba histolytica/genética; Entamoeba histolytica/enzimología; Entamoeba histolytica/metabolismo; Secretasas de la Proteína Precursora del Amiloide/metabolismo; Secretasas de la Proteína Precursora del Amiloide/genética; Proteínas Protozoarias/metabolismo; Proteínas Protozoarias/genética; Membrana Celular/metabolismo; Filogenia; Humanos

Palabras clave

Aspartyl protease; Entamoeba histolytica; Intramembrane-cleaving proteases; Nicastrin; Presenilin; Regulated intramembrane proteolysis; Î³-Secretase

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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Proteínas Protozoarias / Entamoeba histolytica / Secretasas de la Proteína Precursora del Amiloide / Proteolisis Límite: Humans Idioma: En Revista: Parasitol Int Asunto de la revista: PARASITOLOGIA Año: 2024 Tipo del documento: Article Pais de publicación: Países Bajos

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