Cell-to-cell communication

Question 1

Gap junctions

Answer 1

• hexameric channels that allow the diffusion of small molecules between two connected cells
• 6 connexions arrange in a ring like structure to form a connexon

Question 2

Familial atrial fibrillation

Answer 2

• most common cardiac arrhythmia
• atrial tissue expresses Cx40 and Cx43
• connexins are normally at the polar ends of myocytes in the intercalated discs
• connexin trafficking defects-reduction in gap junctional conductance and altered expression of Cx40

Question 3

Charcot-Marie-Tooth Neuropathy

Answer 3

• inherited disease
• affects peripheral nerves
• gait problems in infancy or later in childhood

Question 4

Receptor Tyrosine Kinases

Answer 4

adds a phosphate group to a molecule

adds the phosphate to tyrosine residues