Non-Histone Nuclear Proteins : Patterns of Synthesis and Phosphorylation During the Cell Cycle, Redistribution at Times of Gene Activation and Properties of Subsets Interacting with HnRNA

<p>The interphase nucleus contains large numbers of nonhistone proteins, the majority of which are associated with chromatin. The amount and number of these proteins varies according to cell type. Actively proliferating cells with high transcriptional activity contain considerably more nonhistone nuclear proteins than do quiescent cells. In every cell type, the nuclear proteins are heterogeneous ; recent estimates based on two-dimensional gel electrophoresis place the total number of different HeLa cell chromosomal proteins at over 470 (Peterson and McConkey, 1976). Many of these proteins exhibit enzymatic activities associated with nuclear functions (such as DNA synthesis and repair, RNA synthesis, post-synthetic modifications of histones and nucleic acid, nuclear energy metabolism, chromosome movement, etc...). However, most of the nuclear proteins do not appear to be enzymes, and are therefore difficult to analyze or classify. In general, two groups of proteins may be distinguished: proteins that are structural elements of the nucleus, and proteins that bind to DNA and appear to influence the rate and specificity of RNA synthesis. (Even these two broad categories cannot account for a number of proteins that are transiently associated with chromatin, such as steriod receptors and considerable overlap between these categories undoubtedly exists. ) In this thesis, two different aspects of the non-histone nuclear proteins are examined. In the first part, the nonhistone nuclear proteins are treated as a group, and aspects of their metabolism are examined in synchronized HeLa cells, and in lymphocytes stimulated to proliferate by mitogens. These experiments lend support to the already substantial evidence that many of the nuclear proteins are intimately involved in the control of cell proliferation (Stein and Baserga, 1972; review). The second part describes the chemistry of nuclear RNA-binding proteins. These proteins are likely to be structural elements of chromatin active in transcription.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Thesis

Year

1976

Author dc:creator

• Karn, Jonathan

Contributors dc:contributor

• Vincent Allfrey

• non-histone proteins
• nuclear proteins
• cell cycle
• phosphorylation
• gene activation
• hnRNA interaction
• Life Sciences

Repository record dc:identifier

https://digitalcommons.rockefeller.edu/student_theses_and_dissertations/534

OAI identifier oai:identifier

oai:digitalcommons.rockefeller.edu:student_theses_and_dissertations-1537