| Notch is an essential gene encoding a signalling receptor that is required throughout development to regulate the spatial patterning, timing and outcomes of many different cell fate decisions in both vertebrate and invertebrate species. Notch receptor is a heterodimer and is a single spanning transmembrane protein,which has a modular architecture including signal peptide ,36 like repeats epidermal growth factor (EGF) and three membrane-proximal Linl2/Notch/Glp-1 (LNG) repeats. The intracellular domain has four distinct regions,from the membrane-proximal region they are Su(H)(RBP-JK/CBF-lin mammals) binding domain (RAM23 domain), cdc10/ankyrin repeats, a transcriptional activator domain (TAD) and the PEST (proline-,glutamate-, serine-, threonine-rich) sequence. After Notch receptor is bond by Delta or Serrate(Jagged in mammals), the intracellular domain of Notch is cleaved, mediated by proteolytic enzymewhich has been linked to presenilins-1, which releases the soluble intracellular domain of Notch (Notch-IC), Notch-IC is translocated to the nucleus where it binds via the RAM23 domain and ankyrin repeats to a transcription factor(Su(H)/RBP-JK/CBFl). Notch-IC can displace the corepressor complexes that binding with the DNA-binding protein Su(H)/RBP-JK/CBFl and activate transcription of Notch target genes;But when Notch-IC is not binging with Su(H)/RBP-JK/CBF1, Su(H)/RBP-JK/CBFl can repress transcription through recruitment of a histone deacetylase(HDAC),Terefore, Su(H)/RBP-JK /CBF1 plays a key role as negative regulator of transcription. MINT/spen encodes a large nuclear protein that is highly conserved from C. elegans to human.The MINT/spen protein as a transcriptional corepressor,functioning in the histone deacetylase complex ,ifs negatively regulates Notch signaling by inhibiting Su(H) /RBP-JK /CBFl.To identify the function and mechanism of MINT interacts with Su(H) /RBP-JK/CBFl.Dr Han Hua and H.Honjo's group in Kyoto university set up MINT gene knockout of mouse and succeed, preliminary analyse the MINT gene knockout mouse show homozygous mutant was death after 13.5dpc. Data in pathological analysis indicates the homozygous mutant has abnormality in central nervous system(CNS) ,showing MINT associate to the development of CNS.After succeed get MINT gene knockout mouse .Yeast two-hybrid assay was used to screen proteins that interact with MINT. Because the cDNA of MINT is as long as polypeptide of 10799bp,We cut it into 6 fragments and named F1-F6 respectively.In the present study ,we analyzed the MINT-F2(365-1084) fragment which is cloned into the vector pGBKTT, From 1.0×108 yeast clones transformed with the bait plasmid and a cDNA library of 9 dpc mouse embryo, 128 werepositive for nutritional screening and β-galactosidase assay, Restriction identified that 4 independent positive clones were screened, which are laminin receptor 1 , two of 16S ribosomal RNAand Arginyl-tRNA synthetase.In this study, we get two of 16S ribosomal RNA gene,both of them are mitochondrial RNA, one is mitochondrial gene for mitochondrial produc,which is associated to molecular phylogenetics and the origins of placental mammals; another is mitochondrial gene for nuclear product,It's a novel chimeric mitochondrial RNA Localized in the nucleus of Mouse sperm, It's 16S mitochondrial RNA plus an inverted repeat of 120 bp covalently joined to the 5'end of the RNA, the chimeric RNA is a post-transcriptional product, maybe resulting from a trans splicing reaction, and is present in mouse sperm, testis, liver, kidney,brain,and spleen. We also get a Arginyl-tRNA synthetase, which function is combine arginine and tRNA.And we also get laminin receptor1,Which is a high-affinity laminin-binding protein that is overexpressed on the turner cell surface in a variety of cancers(especially in preleukemic thymuses), the laminin-1 was modificated by laminin receptor 1 and change it's structure and bind enzymes which were specific protease secreted by tumor cell and stromal cells(mainly cysteine proteinase cathepsin B),increased the...
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