The hierarchical structure of the perichromosomal layer comprises Ki67, ribosomal RNAs, and nucleolar proteins

Journal Article · Sat Nov 18 04:00:00 EST 2017 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2017.09.092· OSTI ID:22719138

Hayashi, Yuki; Kato, Kazashi ^[1]; Kimura, Keiji ^[1]

---

1. Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tenno-dai, Tsukuba Science City, Ibaraki 305-8577 (Japan)

The perichromosomal layer (PCL) is a structure that surrounds mitotic chromosomes, found in both animal and plant cells. It comprises various proteins and RNAs, mainly derived from the nucleolus. Several functions for the PCL have been suggested; however, the mechanism of PCL organization during mitosis remains unclear. The localization of several nucleolar proteins to the PCL is reportedly dependent on pre-ribosomal RNAs and the marker of proliferation, Ki67, which is a major PCL-localized protein. Here we demonstrate that, although the removal of pre-ribosomal RNAs from the PCL causes PCL delocalization of several nucleolar proteins, it does not affect the localization of Ki67. Conversely, Ki67 depletion results in the dissociation of both pre-ribosomal RNAs and nucleolar proteins from the PCL, which indicates that Ki67 is required for the PCL accumulation of pre-ribosomal RNAs, to which several nucleolar proteins are associated. Given these findings, we propose a model for PCL organization that comprises three essential layers: the scaffolding protein Ki67, pre-ribosomal RNAs for linkage, and outer nucleolar proteins. - Highlights: • Pre-rRNAs are required for PCL association of several nucleolar proteins. • Pre-rRNAs on the PCL are dispensable for PCL localization of Ki67. • Ki67 is essential for association of pre-rRNAs on the PCL. • PCL consists of inner Ki67, intermediate pre-rRNAs, and outer nucleolar proteins.

• OSTI ID: 22719138
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 2 Vol. 493; ISSN 0006-291X; ISSN BBRCA9
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
ACTINOMYCIN
ALBUMINS
CATTLE
CHROMOSOMES
MITOSIS
PHOSPHATES
RIBOSOMAL RNA
URIDINE