Non-Hisatone Pro,seminar,.pptx

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1. Jimma University Institute of Health Sciences Department of Biomedical Science Course Title: Basics of Genetics Seminal Presentation on:- non-histone proteins By ;- Bikila Belay…RM0435/15-0 Submitted to:- Prof,Kumaresan Ramanathan June 2023 Jimma,Ethiopa

2. CONTENTS: Definition of non histone proteins. Types of non-histone proteins. Non-histone Chromosomal Proteins. Roles of non histone in chromosomal structure.

3. Definition of non histone proteins I s  a DNA-binding nuclear protein expressed throughout the cell cycle in proliferating cells, but not in quiescent (G0) cells. The non-histone proteins , are a large group of heterogeneous proteins that play a role in organization and compaction of the chromosome into higher order structures. Non-histone proteins are those proteins in chromatin that persist after the removal of the histones. The chromosome is organized and compacted into higher-order structures by a wide group of heterogeneous proteins known as non-histone proteins .

4. Nonhistone proteins Hundreds of other proteins that make up chromatin and are not histones 200 – molecules of each kind of no histone protein. Large variety of functions -Structural role – chromosome scaffold . -Chromosome replication – e.g. DNA polymerases. -Chromosome segregation – e.g. kinetochore proteins .

5. C ont….. -Active in transcription – - largest group the motor proteins of kinetochores help during mitosis and meiosis. -By interacting with DNA, influence when, where , and at what rate genes give rise to their protein products. - Non histone proteins are not a part of a nucleosome. - Non histone proteins are not conserved across species. - Non histone proteins are not involved in gene expression regulation.

6. Types of non-histone proteins -Scaffold proteins , - Heterochromatin Protein 1, -DNA polymerase , -Polycomb , etc. are some types of non histones and -other motor proteins, which are essential for cell organization.

7. Non-histone Chromosomal Proteins: - Relatively low in abundance compared to the histones - They include: 1) proteins for transcription (SSB DNA poly etc. - RNA polymerases - activators and repressors (later disc.) ( Transcription Factors) 2) DNA polymerase for replication. 3) High Mobility Group (HMG) proteins. - moderately abundant ( average 1 HMG/nucleosome) - role in transcription - Structural? - Functional? - later disc. 4) Other structural proteins (Topoisomerase, etc .)

8. Non-histone Chromosomal Proteins Structural Maintenance of Chromosome proteins (SMC proteins) Can hold two circular DNA molecules together Most interesting: SMC proteins may reside in the chromosome scaffold and help establish the radial loops

9. Non-histone Chromosomal Proteins: They play vital roles in:- -regulating processes like nucleosome remodeling , - DNA replication ,& DNA damage repair. - RNA synthesis and processing, - nuclear transport ,/ signal transduction - steroid hormone action and - interphase/mitosis transition . -autophagy and metabolism. The main function of non histone proteins is the compaction of chromatin in chromosomes and organization of chromosomes inside the nucleus

10. Roles of non histone in chromosomal structure: Non histone protein helps maintain chromosome structure: - The assembly of non histone proteins and the structural integrity of vertebrate mitotic chromosomes depend on condensin.

11. Reference : Woodcock, C.L.; Ghosh, R.P. Chromatin Higher-order Structure and Dynamics.  Gold Spring Harb. Perspect. Biol.   2010 , a000296. [ Google Scholar ] [ CrossRef ] [ PubMed ] Bekhor, I., Kung, G.M. & Bonner, J. (1969). Sequence-specific interaction of DNA and chromosomal protein.  J. Mol. Biol.   39 , 351– 364 Bhorjee, J.S. & Pederson, T. (1972). Nonhistone chromosomal proteins in synchronized HeLa cells.  Proc. Natl. Acad. Sci. U.S.A.   69 , 3345–  3349  Curtis Seubert. “The Difference Between Histone & Nonhistone.” Sciencing. Leaf Group, 24 Apr. 2017. Web. 15 May 2017.