Functional expression of transcobalamin II cDNA in Xenopus laevis oocytes.
The products of in vitro transcription of human transcobalamin II (TC II) cDNA when microinjected into Xenopus laevis oocytes yielded a single secretory protein of 43 kDa. The mobility of the 43 kDa band did not change following digestion with peptide N-glycosidase F. [57Co]Cbl bound to the medium was immunoprecipitated with anti-serum to human TC II, but not to other Cbl binders. In addition, the [57Co]Cbl complex also bound to placental microsomes. These results suggest that TC II mRNA transcribed encodes TC II which contains both the Cbl and receptor binding domains. Furthermore, Xenopus oocytes can be used as a screening system to define structural elements important in TC II's secretion and binding reactions.
Seetharam
S
S
Department of Medicine, Medical College of Wisconsin, Milwaukee 53226.
Dahms
N
N
Li
N
N
Seetharam
B
B
D000818:Animals; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D006801:Humans; D008715:Methionine / Q000378:metabolism; D009865:Oocytes / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D014155:Transcobalamins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D014158:Transcription, Genetic; D014805:Vitamin B 12 / Q000378:metabolism; D014982:Xenopus laevis
D012333:RNA, Messenger; D011994:Recombinant Proteins; D014155:Transcobalamins; D004247:DNA; D008715:Methionine; D014805:Vitamin B 12