Chapter 1 Isolation and Characterization of Karyoskeletal Pro tein-Enriched Fractions from Vertebrate Livers

Abstract

Publisher Summary This chapter discusses methods for the isolation and subfractionation of vertebrate liver nuclei to produce relatively insoluble karyoskeletal protein-enriched fractions. Morphologically, these fractions contain nuclear pore complexes attached to the lamina and, in several instances, a meshwork of filaments apparently derived from the nuclear interior. The chapter describes methods based on the nuclear purification together with modifications. Morphological features are represented diagrammatically. The nucleus is separated from the surrounding cytoplasm by a system of membranes known as the nuclear envelope. The nuclear envelope is composed of two membranes: the inner nuclear membrane, facing the peripheral chromatin and the outer nuclear membrane, exposed to the cytoplasm and continuous with the rough endoplasmic reticulum. The outer nuclear membrane is typically studded with ribosomes and is morphologically indistinguishable from the membranes of the rough endoplasmic reticulum. The outer and inner nuclear membranes are separated by the perinuclear space, which is continuous with the lumen of the rough endoplasmic reticulum. The perinuclear space is interrupted at various locations where outer and inner nuclear membranes fuse.