Cells expressing mutants of the A and C types of these proteins, which are resistant to caspase-6-mediated degradation, do not fully undergo pyknosis (“pick-noh-siss”). ZMPSTE24 normally removes the C-terminal section of one of these proteins with a farnesylated (“far-NEH-sill-ay-ted”) CAAX (“cax”) box, which is retained in dominant-negative G608G splice-site mutants. The amateur geneticist Jill Viles linked mutations in one of these proteins to both the Olympic athlete Priscilla Lopes-Schliep’s enhanced musculature and her own family’s Emery–Dreifuss muscular dystrophy. MPF phosphorylates these proteins to promote disassembly of the organelle they support before mitosis. These proteins may globally regulate heterochromatin organization. A mutant one of these proteins called progerin causes Hutchinson–Gilford progeria. For 10 points, name these intermediate filaments that form a meshwork beneath the nuclear membrane. ■END■