Role of Id family proteins in growth control.
Id proteins (inhibitors of DNA binding/differentiation) are negative regulators of basic helix-loop-helix (bHLH) type transcription factors, which promote the differentiation of various cell types. In addition to their "classical" ability to inhibit cell differentiation, they are able to stimulate cell cycle progression. These facts suggest that Id proteins play a role in keeping precursor cells immature and in expanding the cell population size during development. In vitro as well as in vivo analyses in the last several years have shown that Id proteins have more complex activities; they induce apoptosis or function as survival factors, depending on the cell context. Furthermore, dysregulated expression of Id proteins has been reported in several human tumors and seems to be related to the malignant character of tumors. Here, we summarize and discuss the biological activities of Id proteins from the standpoint of cell growth control.
Yokota
Yoshifumi
Y
Department of Biochemistry, Fukui Medical University, 23-3 Shimoaizuki, Matsuoka, Fukui 910-1193, Japan. yyokota@fmsrsa.fukui-med.ac.jp
Mori
Seiichi
S
D000818:Animals; D017209:Apoptosis; D002453:Cell Cycle / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology*; D002470:Cell Survival / Q000502:physiology; D016922:Cellular Senescence / Q000502:physiology; D004268:DNA-Binding Proteins / Q000502:physiology*; D018257:Helix-Loop-Helix Motifs; D006801:Humans; D051798:Inhibitor of Differentiation Protein 1; D012097:Repressor Proteins; D013234:Stem Cells / Q000502:physiology; D014157:Transcription Factors / Q000502:physiology*
D004268:DNA-Binding Proteins; C497453:ID1 protein, human; D051798:Inhibitor of Differentiation Protein 1; D012097:Repressor Proteins; D014157:Transcription Factors