Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Más filtros

Banco de datos
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
J Cell Biol ; 153(2): 283-94, 2001 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-11309410

RESUMEN

Proteins with expanded polyglutamine (polyQ) tracts have been linked to neurodegenerative diseases. One common characteristic of expanded-polyQ expression is the formation of intracellular aggregates (IAs). IAs purified from polyQ-expressing cells were dissociated and studied by protein blot assay and mass spectrometry to determine the identity, condition, and relative level of several proteins sequestered within aggregates. Most of the sequestered proteins comigrated with bands from control extracts, indicating that the sequestered proteins were intact and not irreversibly bound to the polyQ polymer. Among the proteins found sequestered at relatively high levels in purified IAs were ubiquitin, the cell cycle-regulating proteins p53 and mdm-2, HSP70, the global transcriptional regulator Tata-binding protein/TFIID, cytoskeleton proteins actin and 68-kD neurofilament, and proteins of the nuclear pore complex. These data reveal that IAs are highly complex structures with a multiplicity of contributing proteins.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Péptidos/metabolismo , Factores de Transcripción/metabolismo , Ubiquitinas/metabolismo , Actinas/metabolismo , Anciano , Línea Celular , Tamaño de la Célula , Cuerpo Estriado/citología , Genes Reporteros , Humanos , Proteína Huntingtina , Etiquetado Corte-Fin in Situ , Microscopía Fluorescente , Persona de Mediana Edad , Proteínas del Tejido Nervioso/metabolismo , Péptidos/genética , Proteínas Recombinantes de Fusión/metabolismo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Proteína de Unión a TATA-Box , Transfección
2.
J Physiol ; 508 ( Pt 3): 667-80, 1998 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-9518724

RESUMEN

1. Differential expression of myosin heavy chain (MHC) isoforms dramatically affects mechanical and energetic properties of skeletal muscle fibre types. As many as five different fibre types, each with different mechanical properties, have been reported in frog hindlimb muscles. However, only two frog MHC isoforms have previously been detected by SDS-PAGE and only one adult hindlimb MHC isoform has been cloned. 2. In the present study, four different fibre types (type 1, type 2, type 3 and tonic) were initially identified in adult Rana pipiens anterior tibialis muscle based on myosin ATPase histochemistry, size and location. Each fibre type exhibited unique reactivity to a panel of MHC monoclonal antibodies. Single fibre analysis using SDS-PAGE revealed that MHCs from immunohistochemically defined type 1, type 2 and type 3 fibres ran as three distinct isoform bands, while MHC of tonic fibres co-migrated with type 1 MHC. The combined data from immunohistochemistry and SDS-PAGE suggests that Rana fibre types are composed of four different MHCs. 3. Four novel MHC cDNAs were cloned and expression of the corresponding transcripts was measured in single immuno-identified fibres using specific polymerase chain reaction (PCR) primer pairs. Each of the four transcripts was found to be primarily expressed in a different one of the four fibre types. 4. Coexpression of MHC isoforms was observed only between types 1/2 and types 2/3 at both the protein and mRNA level. 5. These data provide a molecular basis for differentiation between frog fibre types and permit future molecular studies of MHC structure/function and gene regulation in this classic physiological system. 6. Comparison of sequence homology among amphibian, avian and mammalian MHC families supports the concept of independent evolution of fast MHC genes within vertebrate classes subsequent to the amphibian/avian/mammalian radiation.


Asunto(s)
Isoenzimas/genética , Fibras Musculares Esqueléticas/clasificación , Fibras Musculares Esqueléticas/enzimología , Cadenas Pesadas de Miosina/genética , Adenosina Trifosfatasas/metabolismo , Animales , Diferenciación Celular/genética , Clonación Molecular , Regulación del Desarrollo de la Expresión Génica/fisiología , Isoenzimas/metabolismo , Masculino , Datos de Secuencia Molecular , Fibras Musculares Esqueléticas/citología , Músculo Esquelético/citología , Músculo Esquelético/enzimología , Cadenas Pesadas de Miosina/metabolismo , ARN Mensajero/análisis , Rana pipiens , Homología de Secuencia de Aminoácido
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA