Which of the following is most likely an example of signaling through a transmembrane receptor? 1. The influenza virus recognizes specific proteins on the surface of host cells, causing the entrance of genetic materials into the cytoplasm of the host cells.
2. Low-density lipoproteins (LDL) bind to receptor proteins found on the membrane of receiving cells, triggering its internalization into the receiving cells.
3. The binding of interleukin-6 (IL-6) to the interleukin-6 receptor causes the activation of protein kinases in the cytoplasm, activating the transcription factor NF-κB.
4. The binding of aldosterone to the aldosterone receptor activates its transcription activity, leading to the transcription of genes that promote the uptake of ions and water.