Back to Blog
Ypsilon minus by Herbert W. Franke5/25/2023 Immunolocalization studies at the light and electron microscopic level have shown that protein NO145 is exclusively located in a cage-like cortical structure around the entire nucleolus, consisting of a meshwork of patches and filaments that dissociates upon reduction of divalent cations. Antibodies specific for this protein have allowed its recognition in immunoblots of karyoskeleton-containing fractions of oocytes from different Xenopus species and have revealed its presence in all stages of oogenesis, followed by a specific and rapid degradation during egg formation. The amino acid sequence of this polypeptide with a SDS-PAGE mobility corresponding to M r 145,000 has been deduced from a cDNA clone isolated from a Xenopus laevis ovary expression library and defines a polypeptide of 977 amino acids with a calculated mass of 111 kDa, with partial sequence homology to a synaptonemal complex protein, SCP2. Here, we report the molecular characterization of a novel protein, NO145, which is a major and specific component of a nucleolar cortical skeleton resistant to high salt buffers. Although a number of nonribosomal proteins involved in ribosome formation have been identified, the elements responsible for the shape and internal architecture of nucleoli are still largely unknown. The nucleolus is a ubiquitous, mostly spheroidal nuclear structure of all protein-synthesizing cells, with a well-defined functional compartmentalization.
0 Comments
Read More
Leave a Reply. |