Signal Transduction — Flashcards

Flashcard 21: _____ often presents with increased levels of urinary cAMP due to the activation of Gs proteins when PTH binds its receptor

Answer: Primary hyperparathyroidism

Flashcard 22: 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 23: In the phospholipase C mechanism of cellular signaling, the _____ complex activates phospholipase C, which then catalyzes the liberation of DAG and IP3 from PIP2

Answer: q-GTP

Flashcard 24: _____ activates guanylyl cyclase in the gut, thereby increasing cGMP and fluid secretion.

Answer: Heat-stable toxin

Flashcard 25: Where are estrogen receptors expressed (cell membrane, cytoplasm, nucleus)? _____

Answer: Nucleus

Extra: <b>Receptor Locations:</b> • <b>Cytoplasmic:</b> Glucocorticoids, Mineralocorticoids, Androgens • <b>Nuclear:</b> Estrogen, Progesterone, Thyroid hormone, Vitamin D, Retinoic acid

Flashcard 26: In the adenylyl cyclase mechanism of cellular signaling, the _____ complex activates adenylyl cyclase, which then catalyzes the conversion of ATP to cAMP

Answer: Gαs-GTP

Flashcard 27: _____ of the insulin receptor allows binding of insulin receptor substrate 1 (IRS-1)

Answer: Autophosphorylation

Flashcard 28: The most important of the somatomedins is _____, also known as IGF-1

Answer: somatomedin C

Flashcard 29: The alpha subunit of G proteins has intrinsic _____ activity and may bind GDP (inactive) or GTP (active)

Answer: GTPase

Flashcard 30: Once nitric oxide diffuses into muscle cells, it activates soluble (cytosolic) guanylyl cyclase, which converts _____ to cGMP

Answer: GTP