Figure 3.

Schematic simplified representation of Transforming Growth Factor Beta (TGF-β) signal transduction outside and inside the cell [9,10]. (Graphic: T. Koller.) Legend: (1). TGF-β attaches to the TGF-β receptor on the cell membrane. (2&3). Signalling transcription factors transduce the extracellular TGF-β signalling from the cell-bound TGF-β receptors into the nucleus where they activate or inhibit transcription of TGF-β target genes into the respective mRNA sequences. (4&5). In the cytoplasm the mRNA sequences are translated by ribosomes into proteins. (6). The newly synthesized proteins are either exported out of the cell to form collagen or they are used for intracellular processes.