Lesson 3
Meet MC1R
The Axis of Life
⏱ 0:47Audio Narration
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- Gene: A segment of DNA that provides instructions for building proteins.
- Functional / Wild-type: The original setting of a gene that works as intended.
- Alpha-MSH: The chemical signal that docks onto MC1R to turn it ON.
- Loss-of-function: A mutation that causes a receptor or gene to stop working correctly.
MC1R stands for Melanocortin-1 Receptor. It is a protein that sits on the surface of your melanocytes. When a signal called alpha-MSH docks into it, MC1R turns ON and tells the cell to build eumelanin — the strong, dark shield. In the ancestral human configuration — the way our bodies have worked for over 300,000 years — this switch is always functional. However, when there are mutations in this gene, the switch fails. This 'loss-of-function' means the cell defaults to making pheomelanin. This isn't just about hair color; it's about the fundamental way your body handles light and stress.
Click the switch to see the default biological setting change.
Key Takeaways
- ◈ MC1R is the primary regulator of melanin type.
- ◈ Functional MC1R produces eumelanin; loss-of-function produces pheomelanin.
- ◈ This system has been the human baseline for at least 300,000 years.
Apply Your Intelligence
If MC1R is a switch, what environmental factors might affect how well that switch works?