|
General Comment |
Nucleolin, also known as C23, is an abundantly expressed acidic phosphoprotein of exponentially growing cells and is
located mainly in dense fibrillar regions of the nucleolus. It is involved in the control of transcription of ribosomal
RNA (rRNA) genes by RNA polymerase I, in ribosome maturation and assembly, and in nucleocytoplasmic
transportation of ribosomal components.
NCBI Summary:
Nucleolin (NCL), a eukaryotic nucleolar phosphoprotein, is involved in the synthesis and maturation of ribosomes. It is located mainly in dense fibrillar regions of the nucleolus. Human NCL gene consists of 14 exons with 13 introns and spans approximately 11kb. The intron 11 of the NCL gene encodes a small nucleolar RNA, termed U20.
|
|
Comment |
Trudee Fair et al 2001 reported the immunolocalization of Nucleolar Proteins During
Bovine Oocyte Growth, Meiotic Maturation, and
Fertilization.
During the growth phase of the bovine oocyte transcripts, polypeptides and ribosomes are accumulated in the oocyte to
drive and sustain future meiotic maturation, fertilization, and early embryonic development. The oocyte also furnishes
the early embryo with the components required to establish a functional transcriptionally active nucleolus at the time of
maternal embryonic transition. The temporal localization of nucleolar proteins fibrillarin, nucleophosmin, nucleolin, RNA polymerase I (RNA pol I), upstream binding factor (UBF), and coilin 5P10 was investigated in growing and fully
grown immature bovine oocytes during in vitro maturation and during the first postfertilization cell cycle using
whole-mount immunocytochemistry and confocal microscopy. During the oocyte growth phase, fibrillarin,
nucleophosmin, nucleolin, RNA pol I, and UBF were localized to the oocyte nucleolus. On completion of the growth phase, nucleolin and nucleophosmin appeared to migrate to the periphery of the nucleolus and into the nucleoplasm, and
the proportion of oocytes displaying RNA pol I localization had decreased. Fibrillarin appeared to be localized to large foci within the nucleolus and/or nucleoplasm. Nucleophosmin and
nucleolin labeling was characterized by a homogenous signal over the nucleolus. RNA pol I and UBF were
characterized by the localization of the antibodies to individual or clustered foci in the nucleolus and/or nucleoplasm.
Following oocyte nucleus breakdown (ONBD), the proteins appeared to disperse into the cytoplasm.
|