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Updated: May 5, 2026

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Una señal autónoma para la clasificación basolateral en el dominio citoplasmático del receptor polimérico de

J E Casanova¹, G Apodaca, K E Mostov

¹Department of Anatomy, University of California, San Francisco 94143.

|July 12, 1991

Resumen

Una secuencia específica de 14 aminoácidos en el receptor polimérico de inmunoglobulina lo dirige a la superficie basolateral de las células epiteliales. Esta secuencia actúa como una señal autónoma para la clasificación basolateral, no como un proceso predeterminado.

Área de la Ciencia:

Biología celular Biología celular.
Biología molecular La biología molecular.
Biología celular epitelial Biología celular epitelial

Sus antecedentes:

El receptor polimérico de inmunoglobulina (pIgR) es crucial para el transporte de IgA y IgM poliméricos.
pIgR normalmente se entrega desde el Golgi a la superficie basolateral de las células epiteliales.
Este transporte es esencial para la inmunidad de la mucosa.

Objetivo del estudio:

Para identificar la región específica de pIgR responsable de su localización en la superficie basolateral.
Para determinar si esta región contiene una señal de clasificación autónoma.
Para investigar el mecanismo de clasificación pIgR desde el aparato Golgi.

Principales métodos:

Mutagénesis dirigida al sitio para crear un mutante pIgR que carezca de un segmento de 14 aminoácidos.
Análisis de la localización de proteínas mediante microscopía de inmunofluorescencia.
Evaluación del efecto de la secuencia identificada en la localización de una proteína heteróloga (fosfatasa alcalina placentaria).

Principales resultados:

Un segmento de 14 aminoácidos en el dominio citoplasmático de pIgR lo dirige a la superficie basolateral.
Un pIgR mutante que carece de este segmento se ordena directamente a la superficie apical desde el Golgi.
Esta secuencia de 14 aminoácidos es suficiente para redirigir una proteína apical a la membrana basolateral.

Conclusiones:

La secuencia de 14 aminoácidos identificada contiene una señal autónoma para la clasificación de la membrana plasmática basolateral.
La clasificación basolateral de pIgR no es una vía predeterminada, sino que está regulada activamente por una señal específica.
Este hallazgo proporciona nuevos conocimientos sobre los mecanismos del tráfico de proteínas en las células epiteliales.

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