Question

In the nervous system, __1__ help strengthen the extremely long extensions often present in nerve cell axons; disruptions in these intermediate filaments can lead to neurodegeneration. People who carry mutations in the gene for __2__, an important protein for cross-linking intermediate filaments, have a disease that combines symptoms of epidermolysis bullosa simplex, musculare dystrophy, and neurodegeneration. Humans with progeria, a disease that causes premature aging, carry mutations in a nuclear __3__.

Answer 1

Intermediate filaments are a group of cytoskeletal filaments that contribute to cell structure and maintain the position of the nucleus. Disruptions in intermediate filaments can lead to neurodegeneration, and mutations in specific intermediate filament proteins can result in diseases like epidermolysis bullosa simplex, muscular dystrophy, and progeria.

Step-by-step explanation:

Intermediate filaments are a diverse group of cytoskeletal filaments that act as cables within the cell. They are thicker than microfilaments but thinner than microtubules. Intermediate filaments are made up of fibrous proteins, such as keratin, which strengthen hair, nails, and the skin's epidermis.

Disruptions in intermediate filaments can lead to neurodegeneration. Mutations in the gene for desmin, an intermediate filament protein, can cause a disease that combines symptoms of epidermolysis bullosa simplex, muscular dystrophy, and neurodegeneration.

Progeria, a disease that causes premature aging, is caused by mutations in a nuclear intermediate filament protein called lamins.