Signal logic — What is the process called when inputs from two different signaling molecules are combined to enhance or inhibit a single cellular outcome?

Difficulty: Easy

Correct Answer: Signal integration

Explanation:


Introduction:
Cells rarely act on one signal at a time. They constantly compute decisions from multiple cues. This question focuses on the term for combining messages from distinct signaling pathways to modulate a single downstream effect.


Given Data / Assumptions:

  • Two or more extracellular signals address the same cell.
  • Downstream effect can be enhanced (synergy) or inhibited (antagonism).
  • The cell contains standard pathway components (receptors, transducers, effectors).


Concept / Approach:
Signal integration is the process by which pathways converge and their outputs combine at molecular decision points (e.g., transcription factors, kinase hubs, second messengers). Integration can be additive, synergistic, or antagonistic, allowing nuanced control over proliferation, apoptosis, motility, or metabolism.


Step-by-Step Solution:

1) Identify the problem: multiple signals influence one outcome.2) Locate the molecular nodes: shared kinases, scaffold proteins, or promoters where inputs converge.3) Define the result: the combined effect modulates the magnitude or direction of the cellular response.4) Name the process: signal integration.


Verification / Alternative check:
Examples include ERK signaling integrated with PI3K–Akt at cell cycle entry, or calcium/calmodulin integrating with cAMP at transcriptional control of immediate early genes.


Why Other Options Are Wrong:

  • Signal transduction: general relay of a single pathway, not specifically combining multiple inputs.
  • Signal reception: ligand binding to a receptor, the first step only.
  • Signal amplification: increasing magnitude within a single cascade.
  • Signal termination: turning off pathways via phosphatases or receptor endocytosis.


Common Pitfalls:
Confusing any downstream convergence with amplification. Integration is about combining distinct inputs, not simply boosting one signal.


Final Answer:
Signal integration.

Discussion & Comments

No comments yet. Be the first to comment!
Join Discussion