CLONING, CHARACTERIZATION, AND THE COMPLETE 56.8-KILOBASE DNA-SEQUENCE OF THE HUMAN NOTCH4 GENE

The first complete mammalian genomic sequence reported thus far in the Notch gene family, including a putative promoter region and 30 exons of the human NOTCH4 gene spanning 56.8 kb of DNA, were sequenced. The NOTCH4 locus contains a TATA-less promoter with two putative transcrip tion initiation sites (Inr), three RBP-J kappa sites, and two GATA rec ognition sites. Two cDNA isoforms, NOTCH4(L) and NOTCH4(S), were ident ified. Whereas the NOTCH4(S) isoform contains the entire coding sequen ce, the NOTCH4(L) isoform has two unspliced intronic sequences between exons 11 and 12 and exons 20 and 21 and a misspliced exon 6. Consiste nt with these results, two alternatively spliced isoforms of transcrip ts of approximately 9.3 and 6.7 kb were detected by Northern blot anal ysis. The predicted amino acid sequence of the NOTCH4 protein based on the NOTCH4(S) cDNA sequence contains 2003 amino acids and includes th e predominant motifs of the Notch family: 29 epidermal growth factor ( EGF)-like repeats, 3 Notch/lin-12 repeats, a transmembrane region, 6 c dc10/Ankyrin repeats, and a PEST domain. (C) 1998 Academic Press.