Transforming growth factor-beta: multifunctional regulator of differentiation and development.
Transforming growth factors-beta (TGF-beta) are 25 kilodalton (kDa) homodimeric peptides with multifunctional actions controlling the growth, differentiation and function of a broad range of target cells of both epithelial and mesenchymal derivation. They are expressed early in embryogenesis and their tissue-specific and developmentally dependent expression is strongly suggestive of an essential role in particular morphogenetic and histogenetic events. Five distinct TGF-beta s have been characterized so far, with 65-80% homology to each other. By using both molecular biological and immunohistochemical techniques, we are currently attempting to define specific sites of expression of the different TGF-beta s and to determine whether TGF-beta s 1-5 might have unique functions in development and in the mature organism. Comparative study of the promoter regions for the different TGF-beta s and for any particular TGF-beta in different species is also underway. Mechanistically, TGF-beta s act to control gene expression of their target cells, many of their actions converging on a complex, multifaceted scheme of control of matrix proteins and their interactions with cells; these effects on matrix are thought to mediate many of the effects of TGF-beta on development.
Roberts
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AB
Laboratory of Chemoprevention, National Cancer Institute, Bethesda, Maryland 20892.
Flanders
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KC
Heine
U I
UI
Jakowlew
S
S
Kondaiah
P
P
Kim
S J
SJ
Sporn
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MB
D000595:Amino Acid Sequence; D000818:Animals; D002454:Cell Differentiation; D005314:Embryonic and Fetal Development; D005109:Extracellular Matrix / Q000502:physiology; D006128:Growth; D006801:Humans; D008969:Molecular Sequence Data; D012689:Sequence Homology, Nucleic Acid; D015291:Transforming Growth Factors / Q000235:genetics / Q000502:physiology*
D015291:Transforming Growth Factors