A heterologous expression system for bovine lens transmembrane Main Intrinsic Protein (MIP) in Nicotiana tabacum plants

We have developed a heterologous expression system for transmembrane lens m ain intrinsic protein (MIP) in Nicotiana tabacum plant tissue. A native bov ine MIP26 amplicon was subcloned into an expression cassette under the cont rol of a constitutive Cauliflower Mosaic Virus promoter, also containing a neomycin phosphotransferase operon. This cassette was transformed into Agro bacterium tumefaciens by triparental mating and used to infect plant tissue grown in culture. Recombinant plants were selected by their ability to gro w and root on kanamycin-containing media. The presence of MIP in the plant tissues was confirmed by PCR, RT-PCR and immunohistochemistry. A number of benefits of this system for the study of MIP will be discussed, and also it s application as a tool for the study of heterologously expressed proteins in general.