Smad Transcription Factors (Smad)

Smad transcription factors are intracellular proteins that mediate signaling by the transforming growth factor-beta (TGF-β) superfamily, including TGF-βs, activins, and bone morphogenetic proteins (BMPs). They are crucial for regulating gene expression programs involved in diverse cellular processes such as proliferation, differentiation, apoptosis, and development. Smads are classified into R-Smads (receptor-regulated), Co-Smad (common-mediator), and I-Smads (inhibitory), each playing a distinct role in the signaling pathway. Upon activation by cell surface receptors, R-Smads form complexes with Co-Smad4 and translocate to the nucleus to regulate target gene expression, often in cooperation with other transcription factors. Smad activity is tightly regulated by phosphorylation, ubiquitination, and interactions with other proteins.

Other names

Mothers against decapentaplegic homologSMAD proteins

Modulation of gene expression via DNA binding and interaction with co-factors after activation by TGF-β superfamily receptors.