Insulin Signaling Pathway — Flashcards

Flashcard 1: _____ of the insulin receptor allows binding of insulin receptor substrate 1 (IRS-1)

Answer: Autophosphorylation

Flashcard 2: NF-kB activation pathway: IkB kinase phosphorylates the _____ complex, leading to ubiquitination of IkB

Answer: IkB-NF-kB

Flashcard 3: The most important of the somatomedins is _____, also known as IGF-1

Answer: somatomedin C

Flashcard 4: In the first step of the adenylyl cyclase and phospholipase C mechanism of signaling, binding of hormone to its receptor causes release of _____ from its subunit (s, i, or aq) and replacement by GTP

Answer: GDP

Flashcard 5: PTCH1 is a membrane receptor and a _____ regulator of the Hedgehog signaling pathway.

Answer: negative

Flashcard 6: In the **liver**, _____ stimulates glycogen phosphorylase via **α1** receptors; in the **muscle**, it acts via **β2** receptors.

Answer: epinephrine

Flashcard 7: Activation of a **GPCR** involves the exchange of _____ for _____ on the Gα subunit, leading to its dissociation from the Gβγ complex.

Answer: GDP

Extra: The Gα subunit possesses intrinsic GTPase activity, which hydrolyzes GTP back to GDP to terminate the signal. The GPCR itself acts as a Guanine nucleotide Exchange Factor (GEF) upon ligand binding.

Flashcard 8: Binding of atrial natriuretic peptide to its receptor guanylyl cyclase causes conversion of _____ to cGMP

Answer: GTP

Flashcard 9: Cyclin _____ and Cyclin E-CDK2 drive cells from G1 to S phase

Answer: D-CDK4/CDK6

Flashcard 10: _____ is the only known member of the CX3C chemokine group.

Answer: Fractalkine