Identification of novel paired homeodomain protein related to C. elegans unc-4 as a potential downstream target of MASH1.
A novel paired homeodomain protein, PHD1, that is most closely related to C. elegans unc-4 has been identified by a differential RT-PCR method. PHD1 is expressed in a narrow layer adjacent to the ventricular zone of the dorsal spinal cord, immediately following expression of MASH1 but preceding overt neuronal differentiation. Some cells coexpressing MASH1 and PHD1 can be seen, suggesting that these two genes are sequentially activated within the same lineage. In the olfactory sensory epithelium, PHD1 expression not only follows but is dependent upon MASH1 function, suggesting that PHD1 acts downstream of MASH1. A sequential action of bHLH and paired homeodomain proteins is apparent in other neurogenic lineages and may be a general feature of both vertebrate and invertebate neurogenesis.
Saito
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Tsukuba Life Science Center, RIKEN, Ibaraki, Japan. tesaito@rtc.riken.go.jp
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Anderson
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Mikoshiba
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D000595:Amino Acid Sequence; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D017173:Caenorhabditis elegans / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins / Q000096:biosynthesis*; D005314:Embryonic and Fetal Development; D005260:Female; D018507:Gene Expression Regulation, Developmental; D018257:Helix-Loop-Helix Motifs; D015801:Helminth Proteins / Q000737:chemistry*; D018398:Homeodomain Proteins / Q000096:biosynthesis* / Q000737:chemistry*; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000737:chemistry*; D009297:Nasal Mucosa / Q000196:embryology / Q000502:physiology; D009420:Nervous System / Q000196:embryology / Q000378:metabolism; D009687:Nuclear Proteins; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000096:biosynthesis*
D051792:Basic Helix-Loop-Helix Proteins; D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; D015801:Helminth Proteins; D018398:Homeodomain Proteins; D009124:Muscle Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; C499318:Ascl1 protein, rat; C102937:Uncx protein, rat; C073171:unc-4 protein, C elegans