Cell Signalling and Receptor Mechanisms · USMLE Step 1

Activation of a receptor tyrosine kinase (RTK) most directly causes:

  1. Opening of a plasma-membrane channel for Ca²⁺ influx
  2. Exchange of bound GDP for GTP on a heterotrimeric G protein
  3. Autophosphorylation of the receptor's tyrosine residues
  4. Translocation of the intact receptor into the cell nucleus
Show answer and explanation

Correct answer: Autophosphorylation of the receptor's tyrosine residues

Ligand binding to an RTK induces receptor dimerization and autophosphorylation of its intracellular tyrosine residues, initiating downstream signaling.

Difficulty: Medium Question 2 of 22

Practice all 22 Cell Signalling and Receptor Mechanisms questions

Keep practicing

More Cell Signalling and Receptor Mechanisms questions