Nucleoli (plural of nucleolus) are nuclear organelles located within the nucleus of eukaryotic cells. They are composed of proteins and ribonucleic acid (RNA) and are involved in the production of ribosomes, which play an important role in protein synthesis. This review provides an overview of the structure and function of nucleoli, as well as their role in cell biology and disease.
Structurally, the nucleolus is composed of two distinct regions: the dense fibrillar component (DFC) and the granular component (GC). The DFC is composed of small ribonucleoproteins (RNP) and is the most active part of the nucleolus, involved in the production of ribosomal subunits. The GC is composed of ribosomal RNA (rRNA) and is involved in the assembly of the ribosomal subunits.
Functionally, the nucleolus is responsible for the production of ribosomes. During this process, the DFC assembles the ribosomal subunits, while the GC is involved in the assembly of the mature ribosome. It is also involved in the regulation of gene expression through its interaction with other nuclear and cytoplasmic proteins.
The nucleolus has been found to play a role in several diseases, including cancer. It is believed that alterations in the size and/or structure of the nucleolus can lead to the development of cancer. For example, increased nucleolar size is associated with increased expression of oncogenes, while decreased nucleolar size is associated with decreased expression of tumor suppressor genes.
In conclusion, nucleoli are nuclear organelles located within the nucleus of eukaryotic cells. They are composed of proteins and RNA and are involved in the production of ribosomes. Alterations in the size and/or structure of the nucleolus have been associated with the development of cancer. Further research is needed to better understand the role of the nucleolus in cancer and other diseases.
References
Banerjee, U., & Brangwynne, C. P. (2015). The nucleolus: structure, function and dynamics. Annual review of cell and developmental biology, 31(1), 1-22.
Hermann, A., Lingner, J., & Lührmann, R. (2016). The nucleolus: a key player in cellular life and disease. Trends in biochemical sciences, 41(3), 221-237.
Chen, S., & Yao, P. (2019). Nucleolus: structure, function and involvement in diseases. Nucleus, 10(6), 873-886.