Final answer:
The proteins not commonly known to include oncogenes are ion channels. Oncogenes are usually associated with proteins that regulate cell growth, such as transcription factors, growth factors, and signal-transduction proteins. Ion channels are involved in cellular functions like electrical signaling, not typically in promoting cell division.
Step-by-step explanation:
The group of proteins that is NOT commonly known to include oncogenes is d. ion channels. Oncogenes are cancer-causing genes that result from mutations in genes that typically regulate cell growth and division. These mutations can cause the gene to become overactive, or 'oncogenic,' promoting unrestrained cell proliferation that can lead to cancer. Common proteins associated with oncogenes include transcription factors, growth factors, and signal-transduction proteins, as they directly regulate cell division and growth processes. Ion channels, on the other hand, are typically not associated with oncogenic activity. They facilitate the passage of ions across cell membranes and are more commonly involved in other cellular functions, such as electrical signaling and maintaining the cell's ion balance.
Examples of Oncogene Products
In addition to cyclins, proto-oncogene products are important in the regulation of the cell cycle. These products, such as cell-surface receptors for growth factors and cell-signaling molecules, promote DNA replication and cell division. The gene encoding RAS is a classic example of an oncogene. Over 30 percent of cancer cells have a mutation in the RAS gene that leads to uncontrolled growth, potentially leading to tumor formation and metastasis.
In contrast, tumor suppressor genes like p53 act as a safeguard against unchecked cell division. For instance, when bound by the human papillomavirus (HPV) protein E6, p53—which normally detects and repairs DNA damage—is marked for degradation, thus reducing the capacity of the cell to prevent tumor formation.