Proteins expressed by oncogenes

Proto-oncogene, -Proto-oncogene2 -Proto-oncogenes Proto-oncogene4 -Proto-oncogenes  

Oncogenes that express growth factors and growth factor receptors 

Growth factors are paracrine or endocrine agents, peptides or proteins, released by one cell to regnlate proliferation in adjacent cells (chapter 12) (Table 21.4). Normal cell proliferation requires the presence of growth factors but proliferation of tumonr cells reqnires either no growth factors or much lower concentrations. There are several different characteristics of tumor cells that enable them to respond to very low concentrations of growth factors  

Sis Growth factor Binds to receptor to initiate a signal transduction process. 

Erb-B Growth factor receptor Binds with a growth factor to produce an overactive growth-factor-receptor complex. 

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