Related Experiment Video

Updated: Jun 18, 2026

Detection of the Genome and Transcripts of a Persistent DNA Virus in Neuronal Tissues by Fluorescent In situ Hybridization Combined with Immunostaining
13:22

Detection of the Genome and Transcripts of a Persistent DNA Virus in Neuronal Tissues by Fluorescent In situ Hybridization Combined with Immunostaining

Published on: January 23, 2014

Identification of a cellular protein substrate phosphorylated by the avian sarcoma virus-transforming gene product

E Erikson, R L Erikson

    Cell
    |October 1, 1980
    PubMed

    Insights

    Avian sarcoma virus (ASV) protein pp60src transforms cells by phosphorylating a 34,000-dalton protein. This cellular protein is a direct substrate for pp60src kinase activity in vitro and in ASV-transformed cells.

    Area of Science:

    • Oncology
    • Virology
    • Molecular Biology

    Background:

    • Avian sarcoma virus (ASV) encodes pp60src, a protein kinase implicated in cell transformation.
    • Identifying cellular substrates of pp60src is crucial for understanding viral oncogenesis.

    Purpose of the Study:

    • To identify and characterize cellular proteins phosphorylated by pp60src.
    • To determine if pp60src directly phosphorylates identified substrates in transformation-specific contexts.

    Main Methods:

    • Western blotting to detect protein phosphorylation.
    • In vitro kinase assays using purified pp60src and cellular proteins.
    • Peptide mapping to identify phosphorylation sites.

    Main Results:

    • A 34,000-dalton (34K) cellular protein was identified as a pp60src substrate.
    • Phosphorylation of 34K protein is transformation-specific in ASV-infected avian and mammalian cells.
    • In vitro assays confirmed 34K as a direct substrate for pp60src kinase activity.
    • Phosphorylation occurs at an identical site in vivo and in vitro.

    Conclusions:

    • The 34K protein is a direct cellular target of pp60src kinase activity.
    • pp60src-mediated phosphorylation of the 34K protein contributes to viral transformation.
    • This finding elucidates a key molecular mechanism in ASV-induced oncogenesis.

    More Related Videos

    Purification of Viral DNA for the Identification of Associated Viral and Cellular Proteins08:26

    Purification of Viral DNA for the Identification of Associated Viral and Cellular Proteins

    Published on: August 31, 2017

    Detection and Removal of Nuclease Contamination During Purification of Recombinant Prototype Foamy Virus Integrase07:50

    Detection and Removal of Nuclease Contamination During Purification of Recombinant Prototype Foamy Virus Integrase

    Published on: December 8, 2017

    Related Concept Videos

    Leaky Scanning02:28

    Leaky Scanning

    During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA.  Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for...
    Rous Sarcoma Virus (RSV) and Cancer01:03

    Rous 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...
    PI3K/mTOR/AKT Signaling Pathway01:22

    PI3K/mTOR/AKT Signaling Pathway

    The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a rapamycin-insensitive companion...