Study Of The NSD2 Impact In Autism By Isoform Interactions

Autism Spectrum Disorder(ASD)is a neurodevelopmental disease with a complex and variable pathogenesis.Both genetic and environmental factors are involved in the occurrence of the disease.Among them,60% of the genetic factors contribute to the disease.The typical clinical manifestations of autism are different degrees of interpersonal communication impairment,narrow interest and stereotyped behavior.In appearance,some autistic patients will appear,with special faces,big heads,small heads,muscle atrophy,uncoordinated movement,breathing and Sleep disorders and severe symptoms such as epilepsy.At present,more than hundreds of risk genes have been reported to be closely related to the pathogenesis of ASD.The nuclear receptor SET domain protein(NSD2),also known as MMSET or WHSC1,is a member of the NSD protein family.NSD2 is a key gene of Wolf-Hirschhorn syndrome.Children with this disease are characterized by overgrowth or undergrowth of the brain,respectively,and are accompanied by varying degrees of mental retardation.Developmental disorders of the nervous system play a role in these diseases.However,the research on NSD2 is mainly in the field of tumors.In other developmental mental diseases,especially autism,the research on the mechanism is very scarce.Therefore,studying the role of NSD2 in mental diseases is of great significance for these diseases.Moreover,the gene encoding the NSD2 protein consists of 29 exons,which can be alternatively spliced,resulting in the expression of different transcripts.At present,the research and analysis of most conventional disease networks world-widely are still focused on the gene or protein level,and the more detailed and complex level of splice isomers are ignored.Most of human genes have different degrees of alternative splicing patterns,which may produce different protein isoforms with different expression levels,thereby might have difference in the protein-protein interaction partners.Different isomers of the same gene may have different or even opposite functions.Especially in the brain,more than 90% of genes have different splice isoforms,and these isoforms may have significantly different expressions in different brain tissues and brain development stages.So studying mutations at the genetic level alone misses many important details.To determine the unique function of each transcript of NSD2,we selected four representative transcripts,NSD2-204,NSD2-207,NSD2-208,and NSD2-209.We used immunofluorescence microscopy to locate typical isomers in the cells and found that the location of different transcripts are different.NSD2-204 and NSD2-209 show strict nuclear accumulation,NSD2-207 and NSD2-208 show cytoplasm and nuclear accumulation.We use Label-Free Quantification to perform IP/MS mass spectrometry analysis of transcripts,and obtain the IP/MS mass spectrometry results of each of the five samples.Finally,each isomer was identified and specific protein interaction partners were identified.We constructed a differential network of NSD2 splice isomer interactions and compared themselves to find new disease-related targets.We obtained 890 potential interacting proteins,greatly expanding the database of known NSD2 protein interactions.We then performed a comparative analysis of the potential interacting proteins of each transcript of NSD2.We used the NSD2-204 group as our Reference group and the rest as the Non-Reference group for analysis of related biological functions and molecular pathways.It is worth noting that the reference group(NSD2-204)potentially interacts with proteins in the cell compartment.Associated with the nucleus,consistent with its subcellular distribution.The non-Reference group of potential interacting proteins has a cellular compartment localization that is related to the cytoplasm,such as biological transport,catabolism,etc,consistent with its subcellular distribution.Finally,we classified and enriched NSD2 potential interacting proteins based on exon splicing results.We selected four potential substrate proteins of NSD2 from the functionally enriched group,HNRNPH2,HIST1H1 E,RPL10,and HSPA8.It has been verified that these proteins have been significantly studied in autism and mental retardation.We have systematically incorporated the interaction of selective shear levels into biological network research.Starting from the level of NSD2 cleavage isomers,the relationship between the differential network of NSD2 cleavage isomers and the autism mechanism is studied,and the molecular functional pathways related to NSD2 and autism that can be used as new targets are concluded.