What factors called mitogens stim-ulate cultured mammalian cells to proliferate by inducing expression of early response genes. Many of these genesencode transcription factors that stimulate expression ofgenes encoding the G1/S phase cyclins and E2F transcriptionfactors.

What factors called mitogens stim-ulate cultured mammalian cells to proliferate by inducing expression of early response genes. Many of these genesencode transcription factors that stimulate expression ofgenes encoding the G1/S phase cyclins and E2F transcriptionfactors.

Name: Whatfactors called mitogens stim-ulate cultured mammalian cells to pro
Uploaded: 2024-03-20T06:42:41.000Z
Channel: Bartleby
Description: Whatfactors called mitogens stim-ulate cultured mammalian cells to proliferate by inducingexpression of early response genes. Many of these genesencode transcription factors that stimulate expression ofgenes encoding the G1/S phase cyclins and E2F tr

Biochemistry

6th Edition

ISBN:9781305577206

Author:Reginald H. Garrett, Charles M. Grisham

Publisher:Reginald H. Garrett, Charles M. Grisham

Chapter29: Transcription And The Regulation Of Gene Expression

Section: Chapter Questions

Problem 7P

See similar textbooks

Similar questions

Transcriptional regulators are proteins that bind to promoters (the 5-flanking regions of genes) to regulate their transcription. Assume that a particular transcription regulator normally promotes transcription of gene X, a transport protein. If a mutation makes this regulator gene nonfunctional, would the resulting phenotype be similar to a mutation in gene X itself? Why or why not?
. An interesting mutation in lacI results in repressorswith 110-fold increased binding to both operator andnonoperator DNA. These repressors display a “reverse”induction curve, allowing β-galactosidase synthesis inthe absence of an inducer (IPTG) but partly repressingβ-galactosidase expression in the presence of IPTG. Howcan you explain this? (Note that, when IPTG binds a repressor, it does not completely destroy operator affinity,but rather it reduces affinity 110-fold. Additionally, ascells divide and new operators are generated by thesynthesis of daughter strands, the repressor must findthe new operators by searching along the DNA, rapidlybinding to nonoperator sequences and dissociating fromthem.)
A cloned gene fragment contains a regulatory element that isrecognized by a regulatory transcription factor. Previousexperiments have shown that the presence of a hormone resultsin transcriptional activation by this transcription factor. To studythis effect, you conduct an electrophoretic mobility shift assayand obtain the following results: Explain the action of the hormone.
Phorbol esters have been observed to induce the transcription of AP-1–influenced genes. Explain how this processcould occur. What are the consequences of AP-1 transcription? What role does intermittent exposure to phorbol estershave on an individual’s health?
The transcription factor Pax6 is required continuallyduring the life of a mouse (or a human) for the development and maintenance of the retina. HomozygousPax6 knockout mice die soon after birth because Pax6protein is also required in essential organs, such as thepancreas.a. In order to study the role of Pax6 in eye development, a researcher wants to generate a mouse thatexpresses Pax6 everywhere except in its eyes.Describe how you could construct such a mouse.b. Suppose the scientist wants to create a mousesimilar to that in part (a), but in which the eye cellsfrom which Pax6 function has been removed nowexpress GFP. Marking the cells in this way willallow the investigator to see the shapes of the Pax6−eye cells more easily than if they did not expressGFP. Diagram a Pax6 gene construct that wouldenable her to do this experiment.
Based on its sequence similarity to Apobec1,which deaminates Cs to Us in RNA, activation-induceddeaminase (AID) was originally proposed to work on RNA.But definitive experiments in E. coli demonstrated thatAID deaminates Cs to Us in DNA. The authors of the paperexpressed AID in bacteria and followed mutations in aselectable gene. They found that AID expression increasedmutations about fivefold above the background level inthe absence of AID expression. More importantly, theyfound that 80% of the induced mutations were G→A orC→T. Does this fit with your expectation if AID-inducedmutations arose by deamination of C to U in the DNA?
Certain hormones, such as epinephrine, can increase the levels ofcAMP within cells. Let’s suppose you pretreat cells with or withoutepinephrine and then prepare a cell extract that contains theCREB protein.You then use an electrophoretic mobility shift assay to analyzethe ability of the CREB protein to bind to a DNA fragmentcontaining a cAMP response element (CRE). Describe what theexpected results would be.
The expression patterns as well as activation of different types of CDKs happen at different stages of the cell cycle. Explain why.
Explain the role/importance of the localization of GTPase-activating protein (Ran-GAP) in BOTH nuclear export and import. What would occur if there was a loss of function mutation in Ran-GAP? What would occur if Ran-GAP was localized in the nucleus?
I. The retinoic acid receptor (RAR) is a transcription factor that is similar to steroid hormone receptors. Thesubstance (ligand) that binds to this receptor is retinoicacid. One of the genes whose transcription is activatedby retinoic acid binding to the receptor is myoD. Thediagram that follows shows a schematic view of theRAR proteins produced by genes into which one oftwo different 12-base double-stranded oligonucleotides had been inserted in the ORF. The insertion site(a–m) associated with each mutant protein is indicatedwith the appropriate letter on the polypeptide map.For constructs encoding proteins a–e, oligonucleotide 1(5′ TTAATTAATTAA 3′ read off either strand) wasinserted into the RAR gene. For constructs encoding proteins f–m, oligonucleotide 2 (5′ CCGGCCGGCCGG 3′)was inserted into the gene.NH2 f g h i j k l m COOHa b c d eThe wild-type RAR protein can both bind DNA and activate transcription weakly in the absence of retinoic acid(RA) and strongly in RA’s presence. Each…
Recently, scientists constructed a transgene that expresses a mutant form of Drosophila histone H3 inwhich lysine 27 in the histone tail was changed to methionine (H3K27M). Expression of the H3K27Mtransgene results in aberrant development of fruit fliesbecause of inappropriate expression of many differentgenes. Explain this finding.
The retinoblastoma tumor suppressor gene Rb (RB1) codes forthe retinoblastoma protein (pRB). pRB prevents the progression of the cell cycle through G1 if DNA has been damaged. Itdoes so in part because it binds a transcription-activatingdimer referred to as E2F-DP. The pRB-E2F/DP complex recruits a histone deacetylase to chromatin. Explain.