Regulated nuclear entry of the C. elegans Pax-6 transcription factor.
It is shown that the C. elegans Pax-6 locus encodes two protein isoforms. One contains a Paired DNA binding domain as well as a homeodomain; the other consists only of the carboxy-terminal portion of the locus encoding the homeodomain. These two isoforms are expressed in a variety of postembryonic cell lineages. In one set of lineages, nuclear localization of a homeodomain-only form (MAB-18 isoform) appears to be under temporal and spatial control. Nuclear localization of MAB-18 is correlated with the genetic requirement for mab-18 and with activation of a reporter gene driven by a mab-18 promoter. Reporter gene expression is dependent on mab-18 gene activity. It is hypothesized that a positive feedback loop is activated by regulated nuclear entry.
Zhang
Y
Y
Department of Molecular Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
Ferreira
H B
HB
Greenstein
D
D
Chisholm
A
A
Emmons
S W
SW
D000818:Animals; D001692:Biological Transport; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins; D019070:Cell Lineage; D002467:Cell Nucleus / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000378:metabolism / Q000648:ultrastructure; D005246:Feedback; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D015801:Helminth Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins; D018398:Homeodomain Proteins; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C095405:vab-3 protein, C elegans