Primary Citation of Related Structures:   6I9J
PubMed Abstract: 
Transforming growth factor β is a disulfide-linked dimeric cytokine that occurs in three highly related isoforms (TGFβ1-TGFβ3) engaged in signaling functions through binding of cognate TGFβ receptors. To regulate this pathway, the cytokines are biosynthesized as inactive pro-TGFβs with an N-terminal latency-associated protein preceding the mature moieties ...
Transforming growth factor β is a disulfide-linked dimeric cytokine that occurs in three highly related isoforms (TGFβ1-TGFβ3) engaged in signaling functions through binding of cognate TGFβ receptors. To regulate this pathway, the cytokines are biosynthesized as inactive pro-TGFβs with an N-terminal latency-associated protein preceding the mature moieties. Due to their pleiotropic implications in physiology and pathology, TGFβs are privileged objects of in vitro studies. However, such studies have long been limited by the lack of efficient human recombinant expression systems of native, glycosylated, and homogenous proteins. Here, we developed pro-TGFβ2 production systems based on human Expi293F cells, which yielded >2 mg of pure histidine- or Strep-tagged protein per liter of cell culture. We assayed this material biophysically and in crystallization assays and obtained a different crystal form of mature TGFβ2, which adopted a conformation deviating from previous structures, with a distinct dimeric conformation that would require significant rearrangement for binding of TGFβ receptors. This new conformation may be reversibly adopted by a certain fraction of the mature TGβ2 population and represent a hitherto undescribed additional level of activity regulation of the mature growth factor once the latency-associated protein has been separated.
Related Citations: 
An unusual feature revealed by the crystal structure at 2.2 A resolution of human transforming growth factor-beta 2. Schlunegger, M.P., Grutter, M.G. (1992) Nature 358: 430
Crystal structure of transforming growth factor-beta 2: an unusual fold for the superfamily. Daopin, S., Piez, K.A., Ogawa, Y., Davies, D.R. (1992) Science 257: 369
Structures of a pan-specific antagonist antibody complexed to different isoforms of TGFbeta reveal structural plasticity of antibody-antigen interactions. Moulin, A., Mathieu, M., Lawrence, C., Bigelow, R., Levine, M., Hamel, C., Marquette, J.P., Le Parc, J., Loux, C., Ferrari, P., Capdevila, C., Dumas, J., Dumas, B., Rak, A., Bird, J., Qiu, H., Pan, C.Q., Edmunds, T., Wei, R.R. (2014) Protein Sci 23: 1698
An engineered transforming growth factor beta (TGF-beta) monomer that functions as a dominant negative to block TGF-beta signaling. Kim, S.K., Barron, L., Hinck, C.S., Petrunak, E.M., Cano, K.E., Thangirala, A., Iskra, B., Brothers, M., Vonberg, M., Leal, B., Richter, B., Kodali, R., Taylor, A.B., Du, S., Barnes, C.O., Sulea, T., Calero, G., Hart, P.J., Hart, M.J., Demeler, B., Hinck, A.P. (2017) J Biol Chem 292: 7173
Atomic-resolution structures from fragmented protein crystals with the cryoEM method MicroED. de la Cruz, M.J., Hattne, J., Shi, D., Seidler, P., Rodriguez, J., Reyes, F.E., Sawaya, M.R., Cascio, D., Weiss, S.C., Kim, S.K., Hinck, C.S., Hinck, A.P., Calero, G., Eisenberg, D., Gonen, T. (2017) Nat Methods 14: 399
Organizational Affiliation: 
Proteolysis Lab; Structural Biology Unit; "María-de-Maeztu" Unit of Excellence, Molecular Biology Institute of Barcelona (CSIC); Barcelona Science Park, c/Baldiri Reixac, 15-21, 08028, Barcelona, Catalonia, Spain. xgrcri@ibmb.csic.es.