Proteins Involved in Membrane Transport Between the ER and the Golgi Apparatus: 21 Putative Plant Homologues Revealed by DbEST Searching

Numerous proteins have been identified in yeast and mammalian cells which are involved in trafficking between the endoplasmic reticulum and the Golgi apparatus. A great number of partial cDNA sequences now available from the two major plant model species, Arabidopsis thaliana and Oryza sativa, makes it possible to identify putative plant homologues of known genes/proteins from non-plant species. The authors used this approach to screen the database of Expressed Sequence Tags (dbEST) in order to detect plant homologues of proteins involved in membrane transport between ER and Golgi. Availability of these partial sequences will facilitate the screening of cDNA and genomic libraries otherwise performed using heterologous probes derived from animal and yeast genes. As the plant Golgi complex differs in many respects from its mammalian and yeast counterparts, the dbEST clones found can be directly used for various functional assays (immunoprecipitation, two-hybrid analysis, transgenic plants etc.) to test the exact roles of the encoded proteins and identify their functional partners, some of which may be specific for plants.