The nucleolus: reviewing oldies to have new understandings.
The nucleolus is the most prominent compartment in the nucleus and known as the site for ribosome biogenesis in eucaryotes. In contrast, there is no such equivalent structure for ribosome synthesis in procaryotes. This raises two concerns that how does the nucleolus evolve and that whether the nucleolus remains playing a single role in ribosome biogenesis along the evolution. Increasing data support new nucleolus functions, including signal recognition particle assembly, small RNA modification, telomerase maturation, cell-cycle and aging control, and cell stress sensor. Multiple functions of the nucleolus possibly result from the plurifunctionality of nucleolar proteins, such as nucleolin and Nopp140. Proteomic analyses of human and Arabidopsis nucleolus lead a remarkable progress in understanding the evolution and new functions of nucleoli. In this review, we present a brief history of nucleolus research and new concepts and unresolved questions. Also, we introduce hepatitis D virus for studying the communication between the nucleolus and other subnuclear compartments, and Caenorhabditis elegans for the role of nucleolus in the development and the epistatic control of nucleologenesis.
Lo
Szecheng J
SJ
Department of Life Science, Graduate Institute of Basic Medical Science, 259, Wen-Hwa 1st Road, Chang Gung University, TaoYuan 333. losj@mail.cgu.edu.tw
Lee
Chi-Chang
CC
Lai
Huey-Jen
HJ
D000818:Animals; D017360:Arabidopsis / Q000502:physiology / Q000648:ultrastructure; D017173:Caenorhabditis elegans / Q000502:physiology / Q000648:ultrastructure; D002453:Cell Cycle / Q000502:physiology; D002466:Cell Nucleolus / Q000502:physiology* / Q000648:ultrastructure; D016922:Cellular Senescence / Q000502:physiology; D004843:Epistasis, Genetic; D019143:Evolution, Molecular; D003698:Hepatitis Delta Virus / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D020537:RNA, Small Nucleolar / Q000502:physiology; D018271:Signal Recognition Particle / Q000502:physiology; D019098:Telomerase / Q000502:physiology
D020537:RNA, Small Nucleolar; D018271:Signal Recognition Particle; D019098:Telomerase