title: Endosperm-specific expression of human acid beta-glucosidase in a waxy rice.
abstract: BACKGROUND
  The deficiency of human acid beta-glucosidase (hGCase) causes Gaucher disease, a rare genetically-inherited disorder currently treated by enzyme replacement therapy using recombinant CHO-derived GCase. In an attempt to provide an alternative and more efficient production system, a chimeric cDNA coding for hGCase operatively linked to the signal peptide of rice glutelin 4 (GluB4) was put under the control of the GluB4 endosperm-specific promoter and inserted into the genome of a waxy rice.
  
  
  RESULTS
  Molecular, immunological and biochemical analyses showed that recombinant hGCase, targeted to the protein storage vacuoles of rice endosperm cells, is equivalent to the native protein and has a glycosylation pattern compatible with direct therapeutic use. Compared to a previous study carried out on transgenic tobacco seeds, enzyme contents per unit of biomass were drastically increased; in addition, differently from what observed in tobacco, rice seed viability was unaffected by hGCase even at the highest production level. Transgenic seed polishing combined with a pretreatment of seed flour greatly facilitated hGCase extraction and purification with an industrially-scalable procedure.
  
  
  CONCLUSIONS
  This study opens up the possibility to efficiently produce in the rice seed pharmaceutical compounds which are available in limited amounts or completely excluded from clinical practice due to the inadequacy of their production systems.
authors.affiliation: Transactiva Srl, Via J, Linussio 51, 33100 Udine, Italy. stefano.marchetti@uniud.it.
authors.forename: Tamara
authors.initials: T
authors.lastname: Patti
authors.forename: Bruno
authors.initials: B
authors.lastname: Bembi
authors.forename: Piero
authors.initials: P
authors.lastname: Cristin
authors.forename: Flavia
authors.initials: F
authors.lastname: Mazzarol
authors.forename: Erika
authors.initials: E
authors.lastname: Secco
authors.forename: Carla
authors.initials: C
authors.lastname: Pappalardo
authors.forename: Rita
authors.initials: R
authors.lastname: Musetti
authors.forename: Maurizio
authors.initials: M
authors.lastname: Martinuzzi
authors.forename: Serena
authors.initials: S
authors.lastname: Versolatto
authors.forename: Roberta
authors.initials: R
authors.lastname: Cariati
authors.forename: Andrea
authors.initials: A
authors.lastname: Dardis
authors.forename: Stefano
authors.initials: S
authors.lastname: Marchetti