Cell Signaling: JAK-STAT and RTK Pathways

<p>Tyrosine residues (D)</p> Signup and view all the answers

<p>Phosphorylation of docking sites on the receptor's cytosolic domain (A)</p> Signup and view all the answers

<p>A phosphorylated tyrosine residue (A)</p> Signup and view all the answers

<p>PDZ domains (C)</p> Signup and view all the answers

<p>STAT5 transcription factor (A)</p> Signup and view all the answers

<p>Inhibits apoptosis to allow cell persistence (A)</p> Signup and view all the answers

<p>In the bone marrow (D)</p> Signup and view all the answers

<p>Scaffold proteins contain multiple protein-protein interaction domains. (C)</p> Signup and view all the answers

<p>The SH2 domain requires reversible phosphorylation for binding, whereas SH3 domains bind to proline-rich sequences. (B)</p> Signup and view all the answers

<p>It activates the protein, allowing it to participate in signaling pathways. (A)</p> Signup and view all the answers

<p>It is active at all times but can be modulated by external factors. (B)</p> Signup and view all the answers

<p>The binding relies on the specific molecular complementarity between the SH3 domain and proline-rich residues. (D)</p> Signup and view all the answers

<p>Ligand binding to the external domain (D)</p> Signup and view all the answers

<p>Autophosphorylation of tyrosine residues (C)</p> Signup and view all the answers

<p>They act as molecular switches in signaling pathways (C)</p> Signup and view all the answers

<p>By activating a cascade of cellular events (D)</p> Signup and view all the answers

<p>Docking sites for signaling molecules are created (D)</p> Signup and view all the answers

<p>To phosphorylate additional intracellular proteins. (B)</p> Signup and view all the answers

<p>It regulates cell growth, proliferation, and differentiation. (A)</p> Signup and view all the answers

<p>Feedback loops that fine-tune signaling. (C)</p> Signup and view all the answers

<p>PLCγ pathway (D)</p> Signup and view all the answers

<p>Through a series of protein-protein interactions that involve protein kinases. (B)</p> Signup and view all the answers

Erythropoietin (Epo) binding to two Epo receptors triggers dimerization, bringing JAK kinases closer and activating them via autophosphorylation.

Autophosphorylation, specifically of the activation loop, activates the JAK kinase's ability to phosphorylate other molecules.

JAK kinases are tyrosine kinases, meaning they specifically phosphorylate tyrosine residues, key step for relaying signals.

Epo receptors have three functional domains: extracellular, transmembrane, and cytosolic, each with specific roles in signaling.

Binding of Epo starts a cascade of events, including phosphorylated docking sites (phosphorylation for protein interactions), leading to a cellular response in erythrocyte progenitor cells.

SH2 domains bind to specific sequences on target proteins with high affinity if the target tyrosine is phosphorylated, but with low affinity if it is unphosphorylated.

Specific protein regions that link two different proteins together.

Protein binding that can be turned on and off, like turning a switch.

A protein that controls gene activity related to red blood cell production (erythropoiesis).

This triggers a chain of events, ultimately resulting in red blood cell development, including the activation of STAT5.

A protein that links other proteins together in a signaling pathway.

An adaptor protein with multiple protein-protein interaction domains that assemble proteins in an ordered series.

A protein domain that binds to phosphorylated tyrosine residues.

A protein domain that binds to proline-rich domains on other proteins.

A GTP-binding protein that regulates cellular signaling pathways and has intrinsic GTPase activity.

A type of cell surface receptor that activates signaling pathways when it binds to a specific ligand.

A small protein involved in cell signaling. It acts as a molecular switch by cycling between an active (GTP-bound) and inactive (GDP-bound) state.

The process where two identical RTK receptor molecules bind to each other after ligand binding, forming a dimer. This is crucial for initiating the signaling cascade.

When RTKs get activated, they add phosphate groups to themselves (autophosphorylation). This activates the receptor and creates docking sites for other proteins.

Ras is a key player in relaying signals from RTKs to further downstream pathways, ultimately influencing cell growth, differentiation, and survival.

Ligand binding to Receptor Tyrosine Kinases (RTKs) triggers their activation, leading to phosphorylation events that initiate signal transduction.

A series of protein-protein interactions that relay signals from the cell surface to intracellular targets, often involving phosphorylation cascades.

A signaling pathway involved in regulating cell growth, proliferation, and differentiation.

A signaling pathway crucial for cell survival, growth, and metabolism.

A signaling pathway linked to various cellular responses, including calcium mobilization and cytoskeletal rearrangements.