Expression of a bioactive, single-chain choriogonadotropin in Dictyostelium discoideum.
Human choriogonadotropin (hCG) is a highly complex glycoprotein consisting of two non-covalently associated subunits. We aimed for the expression of a single-chain hCG in the soil amoebae Dictyostelium discoideum, a host which, in principle, provides simple genetics in combination with complex protein synthesis. To limit anticipated problems in mRNA translation, the first 30 bases of the coding sequence were altered to conform to the Dictyostelium preferred codon usage. We show that, immunologically, active single-chain hCG is indeed produced by Dictyostelium. Furthermore, this single-chain hCG is able to bind to the human luteinizing hormone/CG receptor and elicit a biological response. Its receptor-binding affinity is comparable to single-chain hCG produced by mammalian cells. We conclude that Dictyostelium is able to express bioactive highly complex heterologous glycoproteins.
N.V. Organon, Oss, The Netherlands.
J C
JC
Heikoop
P D
PD
Grootenhuis
M
M
Blaauw
J S
JS
Veldema
P J
PJ
Van Haastert
M H
MH
Linskens
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D006063:Chorionic Gonadotropin / Q000235:genetics* / Q000494:pharmacology; D003001:Cloning, Molecular; D006224:Cricetinae; D004023:Dictyostelium / Q000737:chemistry*; D015870:Gene Expression / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D011485:Protein Binding / Q000502:physiology; D021382:Protein Sorting Signals / Q000737:chemistry; D011974:Receptors, LH / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics; D015398:Signal Transduction / Q000502:physiology; D014170:Transformation, Genetic
D006063:Chorionic Gonadotropin; D021382:Protein Sorting Signals; D011974:Receptors, LH; D011994:Recombinant Proteins