Question

DISEASE What modification of MAP (microtubule associated protein tau) causes neurofibrillary tangles in Alzheimer's disease?

a. Hyperphosphorylation of tau protein.
b. Methylation of tau protein.
c. Acetylation of tau protein.
d. Deletion of tau protein.

Answer 1

The modification of tau protein causing neurofibrillary tangles in Alzheimer's disease is hyperphosphorylation, leading to destabilization of microtubules and aggregation of tau into tangles.

Step-by-step explanation:

The modification of Microtubule-Associated Protein Tau (MAPT) that causes neurofibrillary tangles in Alzheimer's disease is the hyperphosphorylation of tau protein. In the brains of individuals with Alzheimer's disease, tau protein undergoes a change where it becomes excessively phosphorylated. This hyperphosphorylation alters the conformation of tau protein, causing it to no longer stabilize microtubules and leading to their disassembly. Consequently, the deformed hyperphosphorylated tau proteins aggregate into neurofibrillary tangles, a hallmark of Alzheimer's pathology, particularly observed in the hippocampus, which is critical for memory.