Protein production

Abstract

The invention concerns the field of protein production and cell culture technology. CERT is identified as a novel in vivo PKD substrate. Phosphorylation on serine 132 by PKD decreases the affinity of CERT towards its lipid target phosphatidylinositol 4-phosphate at Golgi membranes and reduces ceramide transfer activity, identifying PKD as a regulator of lipid homeostasis. The present invention shows that CERT in turn is critical for PKD activation and PKD dependent protein cargo transport to the plasma membrane. The interdependence of PKD and CERT is thus a key to the maintenance of Golgi membrane integrity and secretory transport.

1 - 38 . (canceled) 
     
     
         39 - 67 . (canceled) 
     
     
         68 . A protein of interest or an antibody produced in a cell by a method comprising:
 a. increasing the expression or activity of a protein having an amino acid sequence comprising a steroidogenic acute regulatory related lipid transfer (START) domain or a derivative or mutant thereof; and   b. effecting the expression of said protein of interest.   
     
     
         69 - 75 . (canceled)