Producing recombinant chicken vitellogenin-2 (VTG2) in E. coli involves co-cloning the gene encoding the partial VTG2 protein (26-653aa) into an expression vector with an N-terminal 6xHis-tag gene, followed by transformation into E. coli cells. These cells are cultured under conditions that induce protein expression. Once adequate growth is achieved, the cells are lysed to release the recombinant VTG2 protein, which is purified by affinity chromatography technique. The purity of the recombinant VTG2 protein is confirmed using SDS-PAGE, reaching up to 90%.
Chicken VTG2 is a crucial protein involved in the reproductive biology of chickens. VTG2 plays a significant role in the deposition of yolk mass components, particularly very low-density lipoprotein (VLDL) and vitellogenin (VTG), in chicken oocytes [1]. The protein binds tightly to hen genomic DNA fragments carrying parts of the vitellogenin structural gene, indicating its involvement in gene regulation and expression [2]. Furthermore, the chicken vitellogenin receptor, which binds apolipoproteins, is a member of the low-density lipoprotein receptor (LDLR) superfamily, highlighting its importance in mediating cellular processes related to lipid transport and metabolism [3].
VTG2 is synthesized in the liver of vertebrates and serves as a major yolk precursor protein essential for egg development [4]. Additionally, VTG2 has been identified as a target for estrogen-mediated induction of specific nonhistone chromatin proteins, further emphasizing its role in hormonal regulation and gene expression [5].
References:
[1] H. Bujo, M. Hermann, M. Kaderli, L. Jacobsen, S. Sugawara, J. Nimpfet al., Chicken oocyte growth is mediated by an eight ligand binding repeat member of the ldl receptor family., The Embo Journal, vol. 13, no. 21, p. 5165-5175, 1994. https://doi.org/10.1002/j.1460-2075.1994.tb06847.x
[2] T. Nakayama, Vitellogenin‐specific non‐histone chromatin protein, Embryologia, vol. 28, no. 5, p. 425-429, 1986. https://doi.org/10.1111/j.1440-169x.1986.00425.x
[3] C. Schonbaum, S. Lee, & A. Mahowald, The drosophila yolkless gene encodes a vitellogenin receptor belonging to the low density lipoprotein receptor superfamily., Proceedings of the National Academy of Sciences, vol. 92, no. 5, p. 1485-1489, 1995. https://doi.org/10.1073/pnas.92.5.1485
[4] E. Smith, H. Cheng, & R. Vallejo, Mapping functional chicken genes: an alternative approach, Poultry Science, vol. 75, no. 5, p. 642-647, 1996. https://doi.org/10.3382/ps.0750642
[5] T. Nakayama, M. Irikura, Y. Setoguchi, M. Nakayama, M. Mochizuki, & K. Ogata, Estrogen-mediated induction of a vitellogenin-specific nonhistone chromatin protein in the male chicken liver, MGG Molecular & General Genetics, vol. 201, no. 2, p. 252-257, 1985. https://doi.org/10.1007/bf00425667
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