negative regulation of growth

Definition

Target type: biologicalprocess

Any process that stops, prevents or reduces the rate or extent of growth, the increase in size or mass of all or part of an organism. [GOC:go_curators]

Negative regulation of growth encompasses a complex interplay of molecular mechanisms that control cell proliferation, differentiation, and overall organismal size. It involves a delicate balance between stimulatory and inhibitory signals, ensuring that growth occurs in a controlled and coordinated manner.

Key processes involved in negative regulation of growth include:

1. **Signal transduction pathways:** Extracellular signals, such as growth factors, hormones, and nutrient availability, trigger intracellular signaling cascades that ultimately regulate gene expression and cellular processes related to growth. These pathways often involve protein kinases and phosphatases, which modulate the activity of downstream targets.

2. **Transcriptional regulation:** Transcription factors, proteins that bind to DNA and regulate gene expression, play a crucial role in controlling the synthesis of growth-related proteins. Negative regulators can act as repressors, preventing the transcription of genes involved in cell cycle progression, DNA replication, or protein synthesis.

3. **Cell cycle arrest:** The cell cycle is a tightly regulated process that ensures accurate DNA replication and cell division. Negative regulators can trigger cell cycle arrest at specific checkpoints, preventing uncontrolled proliferation. For example, p53, a tumor suppressor gene, can halt the cell cycle in response to DNA damage, preventing the propagation of mutations.

4. **Apoptosis:** Programmed cell death, or apoptosis, eliminates unwanted or damaged cells. Negative regulators can induce apoptosis in response to excessive growth signals or other stimuli, ensuring proper tissue homeostasis and preventing tumor formation.

5. **Nutrient sensing:** Organisms have evolved intricate mechanisms to sense nutrient availability and adjust growth accordingly. Negative regulators can respond to nutrient deprivation by inhibiting growth processes, conserving resources, and promoting survival.

These regulatory mechanisms are tightly interwoven, ensuring that growth is properly controlled and coordinated. Dysregulation of negative growth regulation can lead to developmental defects, increased susceptibility to disease, and uncontrolled cell proliferation, as seen in cancer.

Examples of specific proteins involved in negative regulation of growth include:

* **TGF-beta:** A growth factor that inhibits the proliferation of many cell types.
* **p53:** A tumor suppressor gene that arrests cell cycle progression in response to DNA damage.
* **Rb:** A protein that regulates the cell cycle by binding to and inhibiting transcription factors.
* **PTEN:** A phosphatase that inhibits signaling pathways involved in cell growth and survival.

The intricate network of negative growth regulators ensures that growth occurs in a controlled and balanced manner, contributing to proper development, tissue homeostasis, and overall organismal health.'
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Proteins (4)

Compounds (1,216)