The region of the viral genome (DNA in DNA tumor-viruses or RNA in RNA-tumor viruses) that can cause a tumor is called an oncogene. This foreign gene can be carried into a cell by the virus and cause the host cell to take on new properties such as immortalization and anchorage-independent growth.
proteins that regulate cell growth
C. proto-oncogenes
Cancer has a chaotic effect on the cell cycle. Cancer typically makes cells reproduce quickly and in an out of control manner.
They are called oncogenes.
It can affect the Carbon Cycle, Nitrogen Cycle and Water Cycle.
Cells are dividing through the processes of Mitosis and Meiosis. DNA mutations directly affect cells by making them divide non-stop. This is known as Cancer. Proto-oncogenes, a gene involved in cell division mutates and becomes oncogenes that orders cell mechanism of division to go on continously even though the DNA found in a cell's nucleus is already damaged. this causes abnormal cell division.
proteins that regulate cell growth
yes
ONCOGENES
proto-oncogenes
Genes called proto-oncogenes stop a cell from dividing too often.
Genes called proto-oncogenes stop a cell from dividing too often.
C. proto-oncogenes
Cancer has a chaotic effect on the cell cycle. Cancer typically makes cells reproduce quickly and in an out of control manner.
Proto-oncogenes are genes whose products promote cell growth and division. They do this by encoding transcription factors that stimulate the expression of other genes, signal transduction molecules that stimulate cell division, or cell cycle regulators that move the ell through the cell cycle. Proto-oncogene products may be located in the plasma membrane, cytoplasm, or nucleus, and their activities are controlled in various ways, including regulation at the transcpritional, translational, and protein-modification levels. When cells become quiescent and cease division, they repress the expression of most proto-oncogene products. In cancer cells, one or more proto-oncogenes are altered in such a way that tier activities cannot be controlled in a normal fashion. This is sometimes due to a mutation in the proto-oncogene resulting in a protein product that acts abnormally. In other cases, proto-oncogenes may encode normal protein products, but the genes are overexpressed or cannot be transcriptionally repressed at the correct time. In these cases, the proto-oncogene product is continually in an "on" state, which may constantly stimulate the cell to divide. When a proto-oncogene is mutated or aberrantly expressed, and contributes to the development of cancer, it is known as an oncogene. Oncogenes are those that have experienced a gain-of-function alteration. As a result, only one allele of a proto-oncogene needs to be mutated or mis-expressed in order to trigger uncontrolled growth. Hence, oncogenes confer a dominant cancer phenotype.
They are called oncogenes.
Proto-Oncogenes have many functions in a cell but they often code for proteins that stimulate cell division, prevent cell differentiation or regulate programmed cell death (apoptosis). For more detailed info see www.news-medical.net/health/What-are-Proto-Oncogenes.aspx for complete article by Sally Robertson (Dec, 2014) including the sources of information.