The Vector 3 is 5.4kb in length, and contains the the amplicin resistance gene, conferring selection of the plasmid in E. coli., the kanamycin resistance gene (neomycin for mammalian selection), and the CMV promoter upstream of the cDNA insert. The SV40 origin allows for replication in mammalian cells, the ColE1 origin is the bacterial origin of replication, and the f1 origin is the filamentous phage origin of replication. The plasmid has multiple cloning sites as shown below. NOTE: the restriction enzymes used in each vector 3 clone is indicated in the product datasheet.
The coding sequence can be easily obtained by digesting the vector with proper restriction enzyme(s). The coding sequence can also be amplified by PCR with primer pair SP6 and T7.
ErbB3, also known as Her3(human epidermal growth factor receptor3), is a member of the epidermal growth factor receptor (EGFR) family of receptor tyrosine kinases. This membrane-bound glycoprotein has a neuregulin binding domain but has not an active kinase domain., and therefore can not mediate the intracellular signal transduction through protein phosphorylation. However, its heterodimer with ErbB2 or other EGFR members responsible for tyrosine phosphorylation forms a receptor complex with high affinity, and initiates the related pathway which lead to cell proliferation or differentiation. ErbB3 has been shown to implicated in numerous cancers, including prostate, bladder, and breast tumors. This protein has different isoforms derived from alternative splicing variants, and among which, the secreted isoform lacking the intermembrane region modulates the activity of membrane-bound form.