Question

Costameres, in which cytosolic actin filaments are linked to extracellular laminins through dystrophin-dystrogylcan complexes, are found in

A) skin cells.
B) intestinal epithelial cells.
C) striated muscle cells.
D) nerve cells.
E) pancreatic cells

Answer 1

Castamere's connect cytosolic actin filaments to the extracellular matrix in striated muscle cells, supporting these cells during contraction.

Step-by-step explanation:

Castamere's are structures in which cytosolic actin filaments are linked to extracellular laminins through dystrophin-dystroglycan complexes. These structures are found in striated muscle cells (option C) where they play a crucial role in connecting the cytoskeleton of muscle cells to the extracellular matrix, thereby helping to transmit the forces generated by muscle contractions. Castamere's support the mechanical integrity of muscle cells during the stress of muscle contractions. Unlike desmosomes, which connect cells together in a sheet-like formation in organs and tissues such as the skin, heart, and muscles, and involving intermediate filaments like keratin, costumeries are specific to the muscle cells helping in their contraction and functional organization.