Cell and Molecular Biology Lecture 35: Gene Regulation in Eukaryotes PDF

11/22/24 Cell and Molecular Biology DR. K. SATA SATHASIVAN Unit 4. Molecular Biology Lecture 35. GENE REGULATION IN EUKARYOTES...

11/22/24 Cell and Molecular Biology DR. K. SATA SATHASIVAN Unit 4. Molecular Biology Lecture 35. GENE REGULATION IN EUKARYOTES times Maite 1 120 years agelimit theoretical Eukaryotic Needs and Genome Organization Eukaryotic Organisms exceptprotists Almost all are multicellular Multiple types of tissues Long life span Growth and development Large genome size 3billionbase pairs Genome (DNA) in nucleus and mitochondria in all eukaryotes. Plants have chloroplast DNA also. 23 mitosomes Nuclear DNA is present in multiple linear PIE chromosomes, and it is compact. Genetic variations due to sexual reproduction and genomic rearrangements 2hm wraparoundhistone 700nm ineachchromatid 2 400nmineachchromosome be 1  11/22/24 Composition of Human Genome only2 RNA Terities V https://link.springer.com/chapter/10.1007/978-3-030-73151-9_1 3 Regulation of Eukaryotic Gene Expression Transcriptional Long term (compaction and methylation of DNA) Short term (transcription factors) Post-Transcriptional Alternate splicing and mRNA stability createvariations Translational I Hormonal control, Timing, Cofactors. Post-Translational Phosphorylation, Zymogen activation. protonpump Developmental regulation seed tree Coordinated regulation Glycolysis Tissue specific gene expression whtis expressed in muscleisnotexpressedinstomach 4 oneshot intake RNAandthenmakeprotein OR don'tmakeRNAandnoprotein 2  11/22/24 Transcriptional – Long Term & Developmental Regulation Evolution of human a-globin and b-globin gene families 3 isaddedto Builtin adenine poitorloseiti.fmmieitteiacicitup 5 Transcriptional – Long Term Regulation DNA rearrangement in the maturation Female Calico cat with black, brown of an immunoglobulin (antibody) gene and white patches due to compacted Bcells inactive X chromosome (Barr body) yb mutate polio cconstant joining irate I 6 3  11/22/24 Transcriptional – Long Term Regulation Transposons / Transposable Elements in DNA Rearrangement it witligegetivat lirofou m.me F 11 pftflologist Tadefunof herforit First Discovered in corn by Barbara McClintock (1902 to 1992). Awarded Nobel Prize in 1983 7 t shawstudiedcorn the stripes stmatictransportation snelgot abunchofvariationcolor germinaltranspor tgenesimppirtersityisnecesssqy.fr Transcriptional – Short Term Regulation A eukaryotic gene and its transcript cisacting elegents 8 4  11/22/24 Transcriptional – Short Term Regulation Three of the major types of DNA-binding A model for enhancer action domains in transcription factors foldy.PEgtompromote patternsl iffsnapes Important for tissue specific gene regulation and coordinated gene expression 9 some are mastergene Post Transcriptional Regulation 11 Alternate splicing and mRNA stability gorenmeii.E.in 1 2 3 4 5 1 2 3 4 5 12 3 5 1 24 5 variation 90 of weusedifferent protein 10 5  11/22/24 Translational Regulation Hormonal control: Prolactin and lactation after child birth milkproteinonlyduringlactatingtime Cofactors: Availability of heme (iron complex) affects the translation of globin mRNA ifyoudon't haveenough Timing of an event: Fertilization here of an egg initiates translation 01000 egg 1 9 Terms 11 Post Translational Regulation Protein degradation anticatin iii AutoRegulation Zymogen activation Modification by Phosphorylation intraits 12 6  11/22/24 Gene Regulation in Eukaryotes Developmental regulation Coordinated gene expression Tissue specific gene regulation Cis-acting Elements: (DNA regulatory sequences) regulategeneexpression Promoter Enhancer Suppressor TATA box etc Trans-acting Factors (proteins that bind to regulatory DNA sequences) Sigma factor TATA box binding proteins Activators Repressors 13 A expressedbasedonthetypeofpromoter where Summary Organization of Eukaryotic Genome Chromosome compaction, repetitive DNA etc. Regulation of Gene Expression Transcriptional Long term: Compaction, deletion, transposition, rearrangement Short term: Transcription factors and cis-acting elements Post-Transcriptional: splicing and mRNA stability Translational: Hormones, timing, cofactors Post-Translational: degradation, modification and zymogen activation Developmental regulation Coordinated gene expression Tissue specific gene regulation 14 7