Host cell properties and external pH affect proinsulin production by Saccharomyces yeast.
The expression of a hybrid gene encoding an alpha-factor prepro leader peptide-miniproinsulin (MPI) fusion [MPI is the same as the LysArg human insulin precursor described by Thim et al. (1986)] was tested in a series of isogenic yeast strains to investigate the influence of some genetic and physiological factors on heterologous production in yeast. We found that: (i) an MF alpha 1 gene disruption in haploid cells, as well as MF alpha 1 gene product expression in diploid cells, do not affect the MPI secretion level; (ii) under conditions of exogenous leucine availability, MPI production is hindered by leucine auxotrophy (a leu2 mutation); (iii) rho- mutations increase the per-cell MPI yield approximately three-fold; (iv) the MPI yield is apparently dependent on the pH of the culture medium: the higher the external pH, the larger the per-cell MPI yield.
Kozlov
D G
DG
Institute of Genetics and Selection of Industrial Microorganisms, Moscow, Russia.
Prahl
N
N
Efremov
B D
BD
Peters
L
L
Wambut
R
R
Karpychev
I V
IV
Eldarov
M A
MA
Benevolensky
S V
SV
D000595:Amino Acid Sequence; D001483:Base Sequence; D006863:Hydrogen-Ion Concentration; D007930:Leucine / Q000378:metabolism; D008969:Molecular Sequence Data; D011003:Ploidies; D011384:Proinsulin / Q000096:biosynthesis* / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000494:pharmacology
C060793:miniproinsulin; D012710:Serum Albumin, Bovine; D011384:Proinsulin; D007930:Leucine