BIOL 200 Chapter Notes - Chapter 3: Nuclear Membrane, Nuclear Pore, Inner Membrane
Document Summary
Inner and outer membrane separated by perinuclear membrane. Outer membrane is connected to er (therefore so is perinuclear space. Cytoplasmic (outer) membrane covered in ribos (like rough er) Inner membrane underlain by nuclear lamina?, a meshwork of intermediate filaments supposting nuclear envelope. During mitosis, nuclear lamina breaks down envelope so chromos can be released and spindles can form. Become phosphorylated and unstable to begin break down. Histone proteins, polymerase, enzymes for replication, ribosomal proteins go in nucleus. Ribo subunits, mrna, fully processed and spliced transcripts exit nucleus. Mutations can change signal, sending proteins to places where they don"t function. Reqd for protein to enter nucleus |( internal targeting seq) Active transport into nucleus: nuclear localization signal ( nls) recognized (found near n-terminus, nls region on nuclear pore binds to import receptor and forms complex. 3)protein/receptor complex binds to cytosouce fibril on nuclear pore. Gtp driven rxn changes configuration of pore, allows protein to enter nucleaus.
