Notch、およびDeltaはともに一回膜貫通型のタンパク質で、DeltaがリガンドとしてNotchにシグナルを伝える。
隣り合った細胞同士で、お互いの細胞外領域が相互作用し、Notchの細胞外ドメインが切断され、さらに細胞内領域も切り離され核内に移動し、細胞内領域は他のタンパク質（ヒストンアセチル化酵素）と複合体を形成して転写因子として標的遺伝子のNotch応答エレメントに結合する。
側方抑制、体節の発生、左右軸の制御など動物の発生に深く関わる。
Neurogenic locus notch homolog protein 1
Short name=Notch 1
Short name=hN1
Alternative name(s):
Translocation-associated notch protein TAN-1
Cleaved into the following 2 chains:
Notch 1 extracellular truncation
Short name=NEXT
Notch 1 intracellular domain
Short name=NICD
Function
Functions as a receptor for membrane-bound ligands Jagged1, Jagged2 and Delta1 to regulate cell-fate determination. Upon ligand activation through the released notch intracellular domain (NICD) it forms a transcriptional activator complex with RBPJ/RBPSUH and activates genes of the enhancer of split locus. Affects the implementation of differentiation, proliferation and apoptotic programs. Involved in angiogenesis; negatively regulates endothelial cell proliferation and migration and angiogenic sprouting. Involved in the maturation of both CD4+ and CD8+ cells in the thymus. Important for follicular differentiation and possibly cell fate selection within the follicle. During cerebellar development, functions as a receptor for neuronal DNER and is involved in the differentiation of Bergmann glia. Represses neuronal and myogenic differentiation. May play an essential role in postimplantation development, probably in some aspect of cell specification and/or differentiation. May be involved in mesoderm development, somite formation and neurogenesis. May enhance HIF1A function by sequestering HIF1AN away from HIF1A. Required for the THBS4 function in regulating protective astrogenesis from the subventricular zone (SVZ) niche after injury. Involved in determination of left/right symmetry by modulating the balance between motile and immotile (sensory) cilia at the left-right organiser (LRO). Ref.13
Subunit structure
Heterodimer of a C-terminal fragment N(TM) and an N-terminal fragment N(EC) which are probably linked by disulfide bonds. Interacts with DNER, DTX1, DTX2 and RBPJ/RBPSUH. Also interacts with MAML1, MAML2 and MAML3 which act as transcriptional coactivators for NOTCH1. Notch 1 intracellular domain interacts with SNW1; the interaction involves multimerized NOTCH1 NICD and is implicated in a formation of an intermediate preactivation complex which associates with DNA-bound CBF-1/RBPJ. The activated membrane-bound form interacts with AAK1 which promotes NOTCH1 stabilization. Forms a trimeric complex with FBXW7 and SGK1. Interacts with HIF1AN. HIF1AN negatively regulates the function of notch intracellular domain (NICD), accelerating myogenic differentiation. Interacts (via NICD) with SNAI1 (via zinc fingers); the interaction induces SNAI1 degradation via MDM2-mediated ubiquitination and inhibits SNAI1-induced cell invasion. Interacts (via NICD) with MDM2A. Interacts (via NICD) with BCL6; the interaction decreases MAML1 recruitment by NOTCH1 NICD on target genes DNA and inhibits NOTCH1 transcractivation activity. Interacts with THBS4 By similarity. Ref.5 Ref.7 Ref.8 Ref.9 Ref.10 Ref.14 Ref.15 Ref.16 Ref.17
Subcellular location
Cell membrane; Single-pass type I membrane protein By similarity.
Notch 1 intracellular domain: Nucleus By similarity. Note: Following proteolytical processing NICD is translocated to the nucleus By similarity.
Tissue specificity
In fetal tissues most abundant in spleen, brain stem and lung. Also present in most adult tissues where it is found mainly in lymphoid tissues.
Post-translational modification
Synthesized in the endoplasmic reticulum as an inactive form which is proteolytically cleaved by a furin-like convertase in the trans-Golgi network before it reaches the plasma membrane to yield an active, ligand-accessible form. Cleavage results in a C-terminal fragment N(TM) and a N-terminal fragment N(EC). Following ligand binding, it is cleaved by ADAM17 to yield a membrane-associated intermediate fragment called notch extracellular truncation (NEXT). Following endocytosis, this fragment is then cleaved by presenilin dependent gamma-secretase to release a notch-derived peptide containing the intracellular domain (NICD) from the membrane By similarity. Ref.18
Phosphorylated By similarity.
O-glycosylated on the EGF-like domains. Contains both O-linked fucose and O-linked glucose. O-linked glycosylation by GALNT11 is involved in determination of left/right symmetry: glycosylation promotes activation of NOTCH1, possibly by promoting cleavage by ADAM17, modulating the balance between motile and immotile (sensory) cilia at the left-right organiser (LRO). Ref.18
Ubiquitinated; undergoes 'Lys-29'-linked polyubiquitination catalyzed by ITCH. Monoubiquitination at Lys-1759 is required for activation by gamma-secretase cleavage, it promotes interaction with AAK1, which stabilizes it. Deubiquitination by EIF3F is necessary for nuclear import of activated Notch. Ref.11
Hydroxylated at Asn-1955 by HIF1AN. Hydroxylated at Asn-2022 by HIF1AN By similarity. Hydroxylation reduces affinity for HI1AN and may thus indirectly modulate negative regulation of NICD By similarity.
Involvement in disease
Aortic valve disease 1 (AOVD1) [MIM:109730]: A common defect in the aortic valve in which two rather than three leaflets are present. It is often associated with aortic valve calcification, stenosis and insufficiency. In extreme cases, the blood flow may be so restricted that the left ventricle fails to grow, resulting in hypoplastic left heart syndrome.
Note: The disease is caused by mutations affecting the gene represented in this entry. Ref.23
Sequence similarities
Belongs to the NOTCH family.
Contains 5 ANK repeats.
Contains 36 EGF-like domains.
Contains 3 LNR (Lin/Notch) repeats.
