CapZ
![This image shows the structures of Cap32/34 superposed onto CapZ (in green) over the Cα positions of the entire CP molecules.[1]](/Images/godic/202501/03/Orthogonal_views_of_cytoplasmic_capping_protein_superposed_onto_its_homolog_CapZ5425.jpg")
In molecular biology CapZ, also known as CAPZ; CAZ1 and CAPPA1, is a protein that caps the barbed (plus) end of actin filaments in muscle cells. It is located in the Z band of the muscle sarcomere.
This protein helps to stabilize the actin filaments protecting it from assembly. The activity regulation of this protein can be done by other regulatory proteins that bind to the actin filaments blocking the CapZ, hence allowing assembly.