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Las secuencias amino-terminales de prosomatostatina apuntan directamente a las células pero no tienen especificidad
K A Sevarino1, P Stork, R Ventimiglia
1Department of Medicine, New England Medical Center Hospital, Boston, Massachusetts 02111.
Cell
|April 7, 1989
Resumen
Los factores celulares, no la secuencia de los precursores, dictan el procesamiento de la somatostatina. Preprosomatostatina de rata (rPPSS) Los residuos N-terminales corrigen los defectos de la prosomatostatina-2 de la anglerfish dirigidos a las células de los mamíferos.
Área de la Ciencia:
- Endocrinología Endocrinología.
- Biología Molecular Biología Molecular
- Biología celular Biología celular.
Sus antecedentes:
- La preprosomatostatina de rata (rPPSS) produce la somatostatina-14 y la somatostatina-28.
- Las islas de pescado pescador producen precursores distintos (a(I) PPSS, a(II) PPSS) para estos péptidos.
- Anteriormente se había observado un procesamiento diferencial de los precursores de la anglerfish.
Objetivo del estudio:
- Investigar la base del procesamiento diferencial entre la preprosomatostatina-1 y la -2.2 de la anglerfish.
- Determinar si los factores celulares o la secuencia de precursores dictan los patrones de procesamiento de la somatostatina.
- Identificar las regiones dentro de los precursores responsables de la correcta orientación y procesamiento.
Principales métodos:
- Líneas celulares endocrinas de mamíferos transfectadas con los vectores de expresión de la preprosomatostatina-1 (a(I) PPSS) y -2 (a(II) PPSS.
- Se analizaron los patrones de procesamiento de ambos precursores de la anglerfish en células de mamíferos.
- Se ha construido y expresado una proteína híbrida que fusiona elementos de preprosomatostatina de rata (rPPSS) con la prosomatostatina-2 del pez pescador.
Principales resultados:
- Tanto a(I) PPSS como a(II) PPSS fueron procesados de manera idéntica en células de mamíferos, lo que indica que los factores celulares controlan el procesamiento.
- La prosomatostatina-2 no procesada de la anglerfish fue secretada constitutivamente a pesar de sitios de procesamiento similares.
- Una proteína híbrida con residuos N-terminales de rPPSS fusionados con a(II)PPSS fue procesada y secretada correctamente a través de una vía regulada.
Conclusiones:
- Los factores celulares, no las diferencias de precursores inherentes, gobiernan los patrones de procesamiento de la somatostatina.
- Los residuos del N-terminal 78 de la preprosomatostatina de rata contienen señales para una correcta orientación y procesamiento.
- Estos hallazgos aclaran los mecanismos moleculares subyacentes al procesamiento diferencial de los precursores de la somatostatina.
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