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Id Proteins Id1 and Id2 Selectively Inhibit DNA Binding by One Class of Helix-Loop-Helix Proteins

Sun, Xiao-Hong and Copeland, Neal G. and Jenkins, Nancy A. and Baltimore, David (1991) Id Proteins Id1 and Id2 Selectively Inhibit DNA Binding by One Class of Helix-Loop-Helix Proteins. Molecular and Cellular Biology, 11 (11). pp. 5603-5611. ISSN 0270-7306. PMCID PMC361931. doi:10.1128/​MCB.11.11.5603.

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The DNA binding activities of some basic region and putative helix-loop-helix (bHLH)-containing transcriptional factors can be inhibited by the Id protein. Because Id contains the HLH motif for dimerization but not the basic amino acid region for DNA binding, heterodimers of Id with bHLH transcriptional factors may not bind to DNA. We have isolated and characterized the gene and cDNA clones for a new Id protein, designated Id2. The Id2 protein contains a helix-loop-helix motif similar to that of the previously described Id protein (referred to here as Idl), but the two proteins are different elsewhere. Idl and Id2 are encoded by two unlinked genes, as shown by chromosome mapping. The two Id proteins have similar inhibitory activities. They selectively bind to and inhibit the function of one set of bHLH proteins, typified by E2A.E47 and E2B.m3, but not that of the other set, including TFE3, USF, and AP4. The Id proteins also homodimerize poorly. Expression of both Id genes is down-regulated during differentiation in a variety of cell types.

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Baltimore, David0000-0001-8723-8190
Additional Information:© 1991 American Society for Microbiology. Received 11 March 1991. Accepted 16 August 1991. We thank R. Benezra and H. Weintraub for the Id1 probe, J. A. Goliger and L. Gudas for the RNA samples from F9 cells, S. Luo and D. Page for the mouse genomic library, Y. Ichikawa and S. Tonegawa for the thymus cDNA library, R. Andino and M. Schlissel for advice, S. Ghosh for reading the manuscript, and D. Swing, D. J. Gilbert, and B. Cho for excellent technical assistance in chromosome mapping. X.-H.S. was supported by a postdoctoral fellowship from the Cancer Research Institute. This work was supported in part by Public Health Service grant GM 39458 (to D.B.) and by the National Cancer Institute, DHHS, under contract N01-CO-74101 with ABL. Addendum: Since the submission of the manuscript, Christy et al. reported the cloning of an Id-like protein named HLH462 (Proc. Natl. Acad. Sci. USA 88:1815-1819, 1991). This protein shares amino acid sequence homology with both Id1 and Id2 in the helix-loop-helix region with some divergence in the loop. HLH462 also contains one of the serine- and threonine-rich homology regions discussed in the text. Because Id1 and Id2 are more closely related, HLH462 should probably be considered Wd3.
Funding AgencyGrant Number
Cancer Research InstituteUNSPECIFIED
NIHGM 39458
National Cancer InstituteUNSPECIFIED
Issue or Number:11
PubMed Central ID:PMC361931
Record Number:CaltechAUTHORS:20120420-071424839
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Official Citation:Id proteins Id1 and Id2 selectively inhibit DNA binding by one class of helix-loop-helix proteins. X H Sun, N G Copeland, N A Jenkins, and D Baltimore Mol. Cell. Biol. November 1991 11:5603-5611; doi:10.1128/MCB.11.11.5603
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:30210
Deposited On:20 Apr 2012 15:04
Last Modified:09 Nov 2021 19:41

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