RNA polymerase II holoenzyme is a form of eukaryotic RNA polymerase II that is recruited to the promoters of protein-coding genes in living cells cite journal It consists of RNA polymerase II, a subset of general transcription factors, and regulatory proteins known as SRB prot...
Clustering of multiple specific genes and gene-rich R-bands around SC-35 domains: evidence for local euchromatic neighborhoods.
- Citation data:
The Journal of cell biology, ISSN: 0021-9525, Vol: 162, Issue: 6, Page: 981-90
- Publication Year:
- Repository URL:
- https://escholarship.umassmed.edu/oapubs/921; https://mouseion.jax.org/stfb2000_2009/666
- Biochemistry, Genetics and Molecular Biology; Cell-Nucleus; Chromosome-Banding; Chromosome-Structures; Collagen-Type-I; DNA-Replication; Euchromatin; Eukaryotic-Cells; Fluorescent-Antibody-Technique; Gene-Expression-Regulation; Human; Multigene-Family; Nuclear-Proteins; RNA-Messenger; SUPPORT-U-S-GOVT-P-H-S; Cell Line; Cell Nucleus; Chromosome Banding; Chromosome Structures; Collagen Type I; DNA Replication; Euchromatin; Eukaryotic Cells; Fluorescent Antibody Technique; Gene Expression Regulation; Humans; Multigene Family; Nuclear Proteins; RNA, Messenger; *Ribonucleoproteins; Cell Biology; Life Sciences; Medicine and Health Sciences
Typically, eukaryotic nuclei contain 10-30 prominent domains (referred to here as SC-35 domains) that are concentrated in mRNA metabolic factors. Here, we show that multiple specific genes cluster around a common SC-35 domain, which contains multiple mRNAs. Nonsyntenic genes are capable of associating with a common domain, but domain "choice" appears random, even for two coordinately expressed genes. Active genes widely separated on different chromosome arms associate with the same domain frequently, assorting randomly into the 3-4 subregions of the chromosome periphery that contact a domain. Most importantly, visualization of six individual chromosome bands showed that large genomic segments ( approximately 5 Mb) have striking differences in organization relative to domains. Certain bands showed extensive contact, often aligning with or encircling an SC-35 domain, whereas others did not. All three gene-rich reverse bands showed this more than the gene-poor Giemsa dark bands, and morphometric analyses demonstrated statistically significant differences. Similarly, late-replicating DNA generally avoids SC-35 domains. These findings suggest a functional rationale for gene clustering in chromosomal bands, which relates to nuclear clustering of genes with SC-35 domains. Rather than random reservoirs of splicing factors, or factors accumulated on an individual highly active gene, we propose a model of SC-35 domains as functional centers for a multitude of clustered genes, forming local euchromatic "neighborhoods."