Abstract

Forhumanstoproperlydevelop,thefertilizedeggmustdivideina mannerthateventuallyresultsinabodythathasallofthecorrectorgansandappendagesinall ofthecorrectplaces.Muchofthisisdeterminedbythepropertemporalandspatialregulation ofmasterregulatorygenesthatguideformationofthedifferentiatedcellsthatmakeuporgans andappendages.Akeyaspectofthisdevelopmentalprocessistheabilitytomaintainmaster regulatorygenesinarepressedstateincellswheretheirexpressionmightcauseinappropriate cellbehavior.Itisknownthatmisexpressionofevenasinglemasterregulatorygene,suchas thoseencodedintheHOXloci,canresultinacellbehavinginamannerincompatiblewithits bodylocationandtissuetype.ThePolycomb-??Group(PcG)groupofgenesislargelyresponsible formaintainingthisrepression,baseduponintensivestudyofthisgroupoverthepast70years. Thisapplicationdescribesthecontinuationofourworkonunderstandingthefunctionofthe proteinsencodedbythePcGgenes.Theseproteinsformseveralcomplexes.Thefocusofthis applicationisPolycombRepressiveComplex1(PRC1),themain?engine?ofrepressioninthe Polycomb-??Group.PRC1isknowntointeractwithchromatin,thestructurethatpackagesgenes inthenucleusofcells.ChromatinstructurecanrendertheenclosedDNAinaccessibleto activatingfactors.Aprominenthypothesisinthefieldhasbeenthatrepressioncanbe generatedbygeneratinghighlypackagedDNAthatisnolongerabletobetranscribedand expressed.WewillinvestigatetherolethatPRC1hasingeneratingpackagedchromatininthe firsttwoAims.Wewillinvestigatehowlongnon-??codingRNAsinterfacewithPRC1toregulate itsfunctioninthethirdAim.Specifically,inAim1wewillstudytheknownabilityofPRC1to interactwithnucleosomes,theprimarybuildingblockofchromatin,toformthemintoa compactedstructure.Wewilltestthehypothesisthatcompactionisessentialtofunctionby analyzingthedevelopmentalphenotypes,inmice,ofmutationsthatimpedetheabilityofPRC1 toformcompactedstructures.
In Aim2 wewillinvestigatetheabilityofPRC1togenerate higher-??orderstructures(onthescaleof100kbofDNA)thatarecompactedasvisualizedby superresolutionmicroscopyandbychromatinconformationcapture.
Aim3 characterizesthe abilityofPRC1complexestobindtolncRNAinvitro.Wewillalsodeveloptechnologiestomap thelocationoflncRNAbindingtochromatinincells.Wewillthencomparetheimpactof specificmutationsinlncRNAsandinPRC1onfunctiontotestthehypothesisthatspecific interactionsbetweenPRC1andlncRNAsareneededforproperfunctionofthePcGsystem.

Public Health Relevance

Afundamentalquestioninbiologyconcernshowasinglefertilizedeggcandevelopinto acorrectlyformedorganism.ThisprocessrequiresthePolycomb-??Group,whichsilences genestomaintainpropercellidentityinmammalsandisinvolvedincancerandin developmentalsyndromes.Wewillcharacterizeproteinsandmolecularmechanisms thatgeneratecompactedchromatinstatesthatmightcausesilencing,andwilldetermine howlongnon-??codingRNAsmightregulatefunctionofthePolycomb-??Group.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM043901-25
Application #
9173260
Study Section
Molecular Genetics B Study Section (MGB)
Program Officer
Carter, Anthony D
Project Start
1991-05-01
Project End
2020-05-31
Budget Start
2016-08-01
Budget End
2017-05-31
Support Year
25
Fiscal Year
2016
Total Cost
Indirect Cost

  Institution

Name
Massachusetts General Hospital
Department
Type
DUNS #
073130411
City
Boston
State
MA
Country
United States
Zip Code

  Publications

Tchasovnikarova, Iva A; Kingston, Robert E (2018) Beyond the Histone Code: A Physical Map of Chromatin States. Mol Cell 69:5-7
Kundu, Sharmistha; Ji, Fei; Sunwoo, Hongjae et al. (2018) Polycomb Repressive Complex 1 Generates Discrete Compacted Domains that Change during Differentiation. Mol Cell 71:191
Ardehali, M Behfar; Anselmo, Anthony; Cochrane, Jesse C et al. (2017) Polycomb Repressive Complex 2 Methylates Elongin A to Regulate Transcription. Mol Cell 68:872-884.e6
Jaensch, Elizabeth S; Kundu, Sharmistha; Kingston, Robert E (2017) Multitasking by Polycomb response elements. Genes Dev 31:1069-1072
Mueller, Britta; Mieczkowski, Jakub; Kundu, Sharmistha et al. (2017) Widespread changes in nucleosome accessibility without changes in nucleosome occupancy during a rapid transcriptional induction. Genes Dev 31:451-462
Tchasovnikarova, Iva A; Timms, Richard T; Douse, Christopher H et al. (2017) Hyperactivation of HUSH complex function by Charcot-Marie-Tooth disease mutation in MORC2. Nat Genet 49:1035-1044
Lau, Mei Sheng; Schwartz, Matthew G; Kundu, Sharmistha et al. (2017) Mutation of a nucleosome compaction region disrupts Polycomb-mediated axial patterning. Science 355:1081-1084
Kundu, Sharmistha; Ji, Fei; Sunwoo, Hongjae et al. (2017) Polycomb Repressive Complex 1 Generates Discrete Compacted Domains that Change during Differentiation. Mol Cell 65:432-446.e5
Ray, Mridula K; Wiskow, Ole; King, Matthew J et al. (2016) CAT7 and cat7l Long Non-coding RNAs Tune Polycomb Repressive Complex 1 Function during Human and Zebrafish Development. J Biol Chem 291:19558-72
Wani, Ajazul H; Boettiger, Alistair N; Schorderet, Patrick et al. (2016) Chromatin topology is coupled to Polycomb group protein subnuclear organization. Nat Commun 7:10291

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