The Interchromatin Compartment Participates in the Structural and Functional Organization of the Cell Nucleus

• Published in: BioEssays Vol. 42; no. 2; pp. e1900132 - n/a
• Main Authors: Cremer, Thomas, Cremer, Marion, Hübner, Barbara, Silahtaroglu, Asli, Hendzel, Michael, Lanctôt, Christian, Strickfaden, Hilmar, Cremer, Christoph
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.02.2020
• Subjects: Accessibility; active nuclear compartment (ANC); chromatin domain (cluster) (CDC); chromosome territory (CT); Euchromatin; Functional morphology; Gene sequencing; Heterochromatin; Hypotheses; inactive nuclear compartment (INC); interchromatin compartment (IC); Macromolecules; Nuclei (cytology); nucleosome cluster (NC); perichromatin region (PR); Regulatory sequences; Ribonucleoproteins; Splicing; Structure-function relationships; Transcription factors; chromatin domain (cluster) (CDC); perichromatin region (PR); inactive nuclear compartment (INC); chromosome territory (CT); active nuclear compartment (ANC); nucleosome cluster (NC); interchromatin compartment (IC)
• ISSN: 0265-9247; 1521-1878
• DOI: 10.1002/bies.201900132

This article focuses on the role of the interchromatin compartment (IC) in shaping nuclear landscapes. The IC is connected with nuclear pore complexes (NPCs) and harbors splicing speckles and nuclear bodies. It is postulated that the IC provides routes for imported transcription factors to target sites, for export routes of mRNA as ribonucleoproteins toward NPCs, as well as for the intranuclear passage of regulatory RNAs from sites of transcription to remote functional sites (IC hypothesis). IC channels are lined by less‐compacted euchromatin, called the perichromatin region (PR). The PR and IC together form the active nuclear compartment (ANC). The ANC is co‐aligned with the inactive nuclear compartment (INC), comprising more compacted heterochromatin. It is postulated that the INC is accessible for individual transcription factors, but inaccessible for larger macromolecular aggregates (limited accessibility hypothesis). This functional nuclear organization depends on still unexplored movements of genes and regulatory sequences between the two compartments. A cell nucleus contains chromosome territories, built from variously sized chromatin domain clusters (red). The space‐time (4D) structure of chromatin domains is currently a matter of intensive research. An interchromatin compartment (green) starts at nuclear pores, expands between domains, and participates in the structural and functional nuclear organization.