Activation of helix-loop-helix proteins Id1, Id2 and Id3 during neural differentiation.
Id is a nuclear factor containing a helix-loop-helix (HLH) motif. It has been reported that Id functions as an inhibitor of cell differentiation and its gene expression is down-regulated during cell differentiation. We have characterized three Id-related cDNAs, Id1, Id2 and Id3, isolated from nerve growth factor (NGF)-stimulated PC12 cells. Structural analysis revealed that all three Id's contain putative phosphorylation sites for cyclic AMP-dependent kinase, casein kinase II and protein kinase C near and inside the HLH motifs. In contradiction to the previous reports, Northern blot analysis revealed that NGF induces rapid and transient increase of all three Id gene transcriptions. Furthermore, in situ hybridization of rat embryo showed that all three Id genes are highly expressed in neural precursors rather than differentiated neural cells. These results indicate that Id family members may function as immediate-early gene products, and that the expression of the Id family may play an important role in the early stage of neural differentiation.
Nagata
Y
Y
Tsukuba Life Science Center, Institute of Physical and Chemical Research RIKEN, Ibaraki, Japan.
Todokoro
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D047388:Casein Kinases; D002454:Cell Differentiation / Q000502:physiology*; D016384:Consensus Sequence; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D017931:DNA Primers; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000302:isolation & purification / Q000378:metabolism; D005333:Fetus / Q000378:metabolism; D015870:Gene Expression; D005865:Gestational Age; D018257:Helix-Loop-Helix Motifs / Q000502:physiology*; D017403:In Situ Hybridization; D051798:Inhibitor of Differentiation Protein 1; D007700:Kinetics; D051379:Mice; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016716:PC12 Cells; D011061:Poly A / Q000032:analysis / Q000096:biosynthesis; D016133:Polymerase Chain Reaction; D011493:Protein Kinase C / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D012097:Repressor Proteins; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors; D014158:Transcription, Genetic
D017931:DNA Primers; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C497454:ID1 protein, rat; C497455:Idb1 protein, mouse; D051798:Inhibitor of Differentiation Protein 1; D009414:Nerve Growth Factors; D012333:RNA, Messenger; D012097:Repressor Proteins; D014157:Transcription Factors; D011061:Poly A; D011494:Protein Kinases; D047388:Casein Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C