A NOVEL ALTERNATIVELY SPLICED FORM OF MURINE VASCULAR ENDOTHELIAL GROWTH-FACTOR, VEGF-115

Murine immortal fibroblasts express a form of vascular endothelial gro wth factor (VEGF) that was cloned, characterized and named VEGF 115, I t differs from VEGF 120 by 37 amino acids at the carboxyl terminus, VE GF 115-specific sequence reacted to a single transcript in mouse tissu es, Reverse transcription-polymerase chain reaction was performed in m ouse tissues and in fibroblasts of normal and immortal divisional phen otypes. The data from mouse tissues suggested that VEGF 115 is not a t issue-specific isoform of VEGF 120, whereas a functional relevance wit h immortalization is indicated from the latter, The novel cDNA was exp ressed in Escherichia coli, and the His-tagged VEGF 115 (17.2 kDa) thu s obtained was recognized by anti-VEGF antibody, A mammalian expressio n plasmid, pCMV(neo+), encoding for VEGF 115 was transfected to NIH 3T 3 cells, and the conditioned medium of stable transfectants was found to have fibroblast growth factor-replacing activity for human umbilica l vein endothelial cells. Two independent genomic PI clonings with pri mers specific for VEGF 164 and VEGF 115, respectively, resulted in iso lation of identical P1 clones, We analyzed these three P1 clones on So uthern blots with common and specific probes for VEGF 164 and VEGF 115 . The results support the hypothesis that VEGF 115 is a new alternativ ely spliced form of mouse VEGF.