PMID: 2462704Sep 1, 1988

Specific kinase activity and phosphorylation state of pp60c-src from neuroblastomas and fibroblasts

X M Yang, G Walter


Several tumor lines of neuronal origin were assayed for the presence of two forms of pp60c-src, designated pp60 and pp60+. To determine the specific kinase activity of pp60 and pp60+, an enzymatic analysis was carried out with neuroblastoma LA-N-5, containing a high level of pp60+, neuroblastoma SK-N-SH, containing a low level of pp60+, fibroblast FSD, containing pp60 but no pp60+, and Rous sarcoma virus transformed 3T3 cells, SR-3T3, containing pp60v-src. Km values for Mg2+-ATP of approximately 21, 8, 17 and 13 microM were determined for pp60src kinase from LA-N-5, SK-N-SH, FSD and SR-3T3 respectively, using enolase as a substrate. The Vmax values for pp60c-src kinase from LA-N-5, SK-N-SH and FSD were similar. The Vmax value of pp60v-src was about 50-fold higher. Thirteen distinct phosphopeptides were found in tryptic digests from pp60 and pp60+ labeled in vivo with [32P]. The presence of one phosphopeptide, derived from the N-terminus, correlated with the level of pp60+ in neuroblastoma cells, but a small amount of this peptide was also detected in fibroblasts. Only phosphoserine was detected in the N-terminus of pp60 and pp60+. Our data strongly suggest that the six extra amino acids, present in pp60+ but not in pp60, do not...Continue Reading

Related Concepts

Neoplasm Proteins
Post-Translational Protein Processing
Protein Tyrosine Kinase
Proto-Oncogene Proteins
Retrovirus Proteins
Tumor Cells, Cultured

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Neural Activity: Imaging

Imaging of neural activity in vivo has developed rapidly recently with the advancement of fluorescence microscopy, including new applications using miniaturized microscopes (miniscopes). This feed follows the progress in this growing field.

The Tendon Seed Network

Tendons are rich in the extracellular matrix and are abundant throughout the body providing essential roles including structure and mobility. The transcriptome of tendons is being compiled to understand the micro-anatomical functioning of tendons. Discover the latest research pertaining to the Tendon Seed Network here.

Myocardial Stunning

Myocardial stunning is a mechanical dysfunction that persists after reperfusion of previously ischemic tissue in the absence of irreversible damage including myocardial necrosis. Here is the latest research.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.


Incretins are metabolic hormones that stimulate a decrease in glucose levels in the blood and they have been implicated in glycemic regulation in the remission phase of type 1 diabetes. Here is the latest research.

Chromatin Regulation and Circadian Clocks

The circadian clock plays an important role in regulating transcriptional dynamics through changes in chromatin folding and remodelling. Discover the latest research on Chromatin Regulation and Circadian Clocks here.

Long COVID-19

“Long Covid-19” describes illness in patients who are reporting long-lasting effects of the SARS-CoV-19 infection, often long after they have recovered from acute Covid-19. Ongoing health issues often reported include low exercise tolerance and breathing difficulties, chronic tiredness, and mental health problems such as post-traumatic stress disorder and depression. This feed follows the latest research into Long Covid.

Spatio-Temporal Regulation of DNA Repair

DNA repair is a complex process regulated by several different classes of enzymes, including ligases, endonucleases, and polymerases. This feed focuses on the spatial and temporal regulation that accompanies DNA damage signaling and repair enzymes and processes.