Video Experimental Relacionado
Updated: Jun 23, 2026
09:20
In situ Subcellular Fractionation of Adherent and Non-adherent Mammalian Cells
Published on: July 24, 2010
El gen del papilomavirus humano tipo 16 E7 codifica funciones de transactivación y transformación similares a las del
W C Phelps1, C L Yee, K Münger
1Laboratory of Tumor Virus Biology, National Cancer Institute, Bethesda, Maryland 20892.
Cell
|May 20, 1988
Resumen
Los virus del papiloma humano (VPH) están relacionados con los cánceres anogenitales, y el VPH-16 se encuentra en la mayoría de los carcinomas cervicales. La proteína HPV-16 E7 muestra similitudes con el adenovirus E1A, que posee funciones de transactivación transcripcional y transformación celular.
Área de la Ciencia:
- Oncología Oncología.
- Virología Virología.
- Biología Molecular Biología Molecular
Sus antecedentes:
- Los estudios clínicos y epidemiológicos implican el virus del papiloma humano (VPH) en las malignidades anogenitales.
- El VPH-16 es el tipo de VPH más frecuentemente detectado en el carcinoma cervical, superando el 60%.
- El VPH-16 se transcribe activamente en los cánceres, con abundantes transcripciones en los primeros marcos de lectura abierta E6 y E7.
Objetivo del estudio:
- Investigar las similitudes funcionales y estructurales entre la proteína E7 del HPV-16 y las proteínas E1A del adenovirus.
- Para determinar si la proteína HPV-16 E7 posee capacidades de transactivación transcripcional y transformación celular.
- Para comparar las funciones de transformación del HPV-16 E7 con las del adenovirus E1A.
Principales métodos:
- Análisis de la actividad del producto del gen HPV-16 E7.
- Los ensayos de transactivación utilizan el promotor E2 del adenovirus.
- Ensayos de co-transformación con un oncogén ras activado en células renales primarias de ratón bebé.
- Ensayos de transformación en células de ratón establecidas.
- Comparación de la secuencia de aminoácidos entre los dominios conservados del HPV-16 E7 y el adenovirus E1A.
Principales resultados:
- El marco de lectura abierto del HPV-16 E7 codifica las funciones de transactivación transcripcional y transformación celular.
- El producto del gen HPV-16 E7 transactivó el promotor del adenovirus E2.
- El HPV-16 E7 cooperó con un oncogén ras activado para transformar las células primarias del riñón de la rata bebé.
- El HPV-16 E7 demostró la capacidad de transformar células de ratón establecidas, una función que no se observó con el adenovirus E1A.
- Se encontraron sorprendentes similitudes entre la secuencia de aminoácidos del HPV-16 E7 y los dominios 1 y 2 conservados de las proteínas E1A del adenovirus.
Conclusiones:
- La proteína HPV-16 E7 exhibe homología funcional y estructural a las proteínas E1A del adenovirus.
- El VPH-16 E7 juega un papel importante en la oncogénesis de las malignidades anogenitales a través de la regulación transcripcional y la transformación celular.
- Los hallazgos contribuyen a comprender los mecanismos moleculares subyacentes a los cánceres inducidos por el VPH.
Videos de Conceptos Relacionados
02:33Retroviruses
Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
02:33Initiation of Translation
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
01:51Mechanisms of Retrovirus-induced Cancers
Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of these viruses are first reverse-transcribed into single and then double-stranded DNA (dsDNA) copies. This dsDNA called proviral DNA then integrates into the host genome. Subsequently, the host cell transcribes the proviral DNA in concert with the chromosomal DNA. This leads to the production of viral RNA and proteins that assemble at the host...
02:38The Ras Gene
The Ras-gene-encoded proteins are regulators of signaling pathways controlling cell proliferation, differentiation, or cell survival. The Ras-gene family in humans constitutes three primary members—the HRas, NRas, and KRas. These genes code for four functionally distinct yet closely related proteins—the HRas, NRas, KRas4A, and KRas4B. The involvement of mutant Ras genes in human cancer was first discovered in 1982 and is among the most common causes of human tumorigenesis.
Ras is a superfamily...
Ras is a superfamily...
01:03Rous Sarcoma Virus (RSV) and Cancer
Rous Sarcoma virus or RSV was discovered by F. Peyton Rous in the year 1911 as a filterable transmissible agent that could cause tumors in chickens. He won a Nobel Prize for this discovery in 1966. His experiments clearly demonstrated that some cancers could be caused by infectious agents and led to the discovery of many more cancer-causing viruses in animals as well as humans.
RSV is a retrovirus that contains two copies of a plus-strand RNA genome. Its genome consists of four main open...
RSV is a retrovirus that contains two copies of a plus-strand RNA genome. Its genome consists of four main open...
01:51Mechanisms of Retrovirus-induced Cancers
Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of these viruses are first reverse-transcribed into single and then double-stranded DNA (dsDNA) copies. This dsDNA called proviral DNA then integrates into the host genome. Subsequently, the host cell transcribes the proviral DNA in concert with the chromosomal DNA. This leads to the production of viral RNA and proteins that assemble at the host...