Polypeptide growth factors in the nucleus: a review of function and translocation

Conventional wisdom declares that polypeptide growth factors act solely by binding to the cell surface and transducing a signal through receptor-mediated kinase cascades; following this, they are endocytosed and degraded. Recent evidence, however, has demonstrated that several growth factors bind to the cell surface and are translocated into the nucleus. Furthermore, these growth factors exert biochemical function within the nucleus. Here we review the growth factors which translocate to the nucleus and/or exert biochemical function within the nucleus, and propose possible translocation mechanisms, including retrograde transport from the cell surface to the nuclear envelope.