Partner of Numb colocalizes with Numb during mitosis and directs Numb asymmetric localization in Drosophila neural and muscle progenitors

Cell. 1998 Oct 16;95(2):225-35. doi: 10.1016/s0092-8674(00)81753-5.


During mitosis of multiple types of precursor cells in Drosophila, Numb is asymmetrically distributed between the two daughter cells and confers distinct daughter cell fates. Here we report the identification of a novel gene product, Partner of Numb (PON), based on its physical interaction with Numb. PON is asymmetrically localized during mitosis and colocalizes with Numb. Loss of pon function disrupts Numb localization in muscle progenitors and delays Numb crescent formation in neural precursors. Moreover, ectopically expressed PON responds to the apical-basal polarity of epithelial cells and is sufficient to localize Numb basally. We propose that PON is one component of a multimolecular machinery that localizes Numb by responding to polarity cues conserved in neural precursors and epithelial cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Carrier Proteins / analysis
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Drosophila / growth & development
  • Drosophila / physiology*
  • Drosophila Proteins*
  • Insect Proteins / genetics
  • Juvenile Hormones / analysis
  • Juvenile Hormones / metabolism*
  • Mesoderm / chemistry
  • Mesoderm / physiology
  • Mitosis / physiology*
  • Molecular Sequence Data
  • Muscle Fibers, Skeletal / chemistry
  • Muscle Fibers, Skeletal / cytology*
  • Mutagenesis / physiology
  • Neurons / chemistry
  • Neurons / cytology*
  • Phenotype
  • Protein Binding / physiology
  • Stem Cells / chemistry
  • Stem Cells / cytology


  • Carrier Proteins
  • Drosophila Proteins
  • Insect Proteins
  • Juvenile Hormones
  • PON protein, Drosophila
  • numb protein, Drosophila

Associated data

  • GENBANK/AF091050