Question

This protein was discovered when it was shown that certain membrane proteins could be related by a phospholipase that specifically recognized and cleaned inositol-containing phospholipids. A rare type of anemia, paroxysmal nocturnal hemoglobinuria, results from deficiency of this protein and makes red blood cells susceptible to lysis. Which protein is it?

a. Membrane carbohydrates
b. Peripheral Membrane Proteins
c. Integral Membrane Proteins
d. Membrane lipases
e. GPI-anchored Proteins

Answer 1

The correct answer is e. GPI-anchored Proteins, which when deficient, lead to an increased susceptibility of red blood cells to lysis, resulting in paroxysmal nocturnal hemoglobinuria.

Step-by-step explanation:

The protein in question, which is implicated in the rare anemia known as paroxysmal nocturnal hemoglobinuria and makes red blood cells susceptible to lysis, is the GPI-anchored Proteins. GPI stands for glycosylphosphatidylinositol, which is the molecule that anchors proteins to the cellular membrane. A deficiency in GPI-anchored proteins causes red blood cells to become more sensitive to lysis because these proteins are involved in protecting the cell from complement, which is part of the immune system that can destroy cells if not properly regulated.