Type:Protein
SpeciesReactivity:H
B=Bovine;Ca=Cat;Ch=Chicken;D=Dog;EQ=Equine;GP=GuineaPig;H=Human;M=Mouse;P=Porcine;Pr=Primate;R=Rat;Rb=Rabbit;Y=Yeast;Xe=Xenopus;Ze=Zebrafish;;;;NA-NotApplicable;STP=Step-TactinProteins;AllGas1(GrowthArrestSpecific1)isoneofsixstructurallyunrelatedproteinsthatwereidentifiedbytheirincreasedexpressioningrowtharrestedcellsrelativetoactivelyproliferatingcells(1,2).Followingmitogenicstimulation,Gas1expressionistranscriptionallysuppressedbycMycascellstransitfromG0toG1phasesofthecellcycle(3,4).OverexpressionofGas1preventsSphaseentryandDNAsynthesis(5).Gas1mediatedblockadeofthecellcycleisp53dependentbutdoesnotrequirethetransactivatingdomainofp53(6).ThehumanGas1CDNAencodesa345aminoacid(aa)precursorthatincludesa39aasignalsequence,a279aamatureprotein,anda27aaCterminalpropeptide.Gas1containsAlarichandAsprichregionsaswellasanRGDsequence(5).MaturehumanandmouseGas1share85%aasequenceidentity.HumanGas1isa40kDaGPIlinkedglycoproteinthatisuniformlydistributedonthecellsurface(7).
Incontactinhibitedvascularendothelialcells,Gas1isinducedbyVECadherinandVEGFexpressionandmediatestheantiapoptoticeffectofVEGF(8).Incontrast,Gas1isinducedinhippocampalneuronsafterNMDAexposurebutfunctionsasaproapoptoticeffectorofNMDAmediatedexcitotoxicity(9).Gas1exhibitsarangeofdevelopmentalactionsincludingeitherpromotingorinhibitinggrowthanddifferentiationofsomite,limb,cerebellar,andeyetissues(1014).Gas1contributestotheantagoNISTiceffectofWntproteinstowardShhfunctionbybindingtheNterminalregionofShh(11).ThedependenceofGas1functiononthecellularcontexthasbeenaddressedbysuggestingthatGas1couldfunctionasacoreceptorforGDNFfamilyligands(15).
