Dj. Jeenes et al., TRANSCRIPTIONAL AND POSTTRANSCRIPTIONAL EVENTS AFFECT THE PRODUCTION OF SECRETED HEN EGG-WHITE LYSOZYME BY ASPERGILLUS-NIGER, Transgenic research, 3(5), 1994, pp. 297-303
The relationship between heterologous gene copy number, mRNA and secre
ted protein yields has been studied in Aspergillus niger transformants
containing either the hen egg-white lysozyme (HEWL) cDNA gene or a gl
ucoamylase-HEWL gene fusion (incorporating the A. niger glaA gene). Th
e results support a direct relationship between HEWL gene copy number,
mRNA and secreted HEWL protein levels at low (<25) copy numbers. High
protein yields are associated with multiple copies of the recombinant
gene at a single site. Fusion of the HEWL gene to the glucoamylase ge
ne resulted in higher steady-state levels of heterologous mRNA. Transf
ormants with the HEWL cDNA alone exhibited a ten-fold higher mRNA:prot
ein ratio than transformants with the gene fusion indicating that post
-transcriptional events significantly affect final secreted protein yi
elds.