Which of the following types of cell signaling involves a cell releasing a signal molecule that binds to receptors on its own surface, thereby affecting itself?

• A. Juxtacrine signaling
• B. Endocrine signaling
• C. Paracrine signaling
• D. Autocrine signaling

Answer: (D)

Verified step by step guidance

1. Understand the concept of cell signaling: Cell signaling is the process by which cells communicate with each other or themselves using signal molecules. Different types of signaling are classified based on the distance the signal travels and the target cell.
2. Define autocrine signaling: Autocrine signaling occurs when a cell releases a signal molecule (such as a hormone or cytokine) that binds to receptors on its own surface, thereby affecting itself. This type of signaling is often used in processes like immune responses or cell growth regulation.
3. Compare autocrine signaling with other types: Juxtacrine signaling involves direct contact between cells, endocrine signaling involves long-distance signaling through the bloodstream, and paracrine signaling involves signaling to nearby cells. Autocrine signaling is unique because the cell affects itself.
4. Identify the key feature of autocrine signaling: The signal molecule does not travel far; it binds to receptors on the same cell that released it. This self-targeting mechanism is the defining characteristic of autocrine signaling.
5. Conclude that the correct answer is autocrine signaling based on the description provided in the problem, as it matches the definition of a cell releasing a signal molecule that affects itself.