JAK STAT Signaling Pathway: Regulation

The video tutorial explains the JAK-STAT pathway, focusing on its activation by various ligands and the subsequent signaling pathways it triggers, such as PI3K AKT and Ras RAF MEK Erk, which promote cell survival. It also covers the phosphorylation and homodimerization of STAT proteins, leading to gene expression. The tutorial discusses negative regulators like protein tyrosine phosphatases, PIAS, and SOCS, which modulate the pathway's activity. SOCS proteins, in particular, are highlighted for their role in JAK degradation through ubiquitination. The video concludes with a summary and directs viewers to additional resources.

Which of the following ligands can activate the JAK-STAT pathway?

• Glucagon

• Adrenaline

• Erythropoietin

• Insulin

What is the role of protein tyrosine phosphatases in the JAK-STAT pathway?

• They enhance STAT dimerization.

• They dephosphorylate JAK and STAT proteins.

• They activate STAT proteins.

• They phosphorylate JAK proteins.

How do PIAS proteins regulate the JAK-STAT pathway?

• By enhancing STAT phosphorylation

• By increasing STAT dimerization

• By inhibiting STAT transactivation

• By promoting JAK activation

What triggers the induction of SOCS proteins?

• Cytokine signaling

• Binding of STAT to DNA

• Constitutive cellular presence

• Phosphorylation of JAK

How do SOCS proteins inhibit the JAK-STAT pathway?

• By increasing cytokine production

• By enhancing STAT dimerization

• By phosphorylating JAK proteins

• By promoting JAK degradation