The N terminus of the Drosophila Numb protein directs membrane association and actin-dependent asymmetric localization

• Published in: Proceedings of the National Academy of Sciences - PNAS 1997-11, Vol.94 (24), p.13005-13010
• Main Authors: Knoblich, J.A, Jan, L.Y, Jan, Y.N
• Format: Article
• Language: English
• Subjects: ACTIN; ACTINA; ACTINE; ANIMAL TRANSGENIQUE; ANIMALES TRANSGENICOS; Animals; ANTIMETABOLITE; ANTIMETABOLITES; ANTIMETABOLITOS; ASYMMETRIC CELL DIVISION; BETA GALACTOSIDASA; BETA GALACTOSIDASE; BIOCHEMISTRY; BIOCHIMIE; Biological Sciences; BIOQUIMICA; Bridged Bicyclo Compounds, Heterocyclic - pharmacology; CELL DIVISION; CELL MEMBRANES; Cell separation; CELL STRUCTURE; CELLS; CELLULE; CELULAS; CYTOCHEMISTRY; CYTOSKELETON; Daughter cells; DIVISION CELLULAIRE; DIVISION CELULAR; Drosophila; Drosophila - metabolism; DROSOPHILA MELANOGASTER; Drosophila Proteins; EMBRYOS; Epidermal cells; Epithelial cells; ESTRUCTURA CELULAR; HISTOENZYMOLOGY; IMMUNOCYTOCHEMISTRY; IMMUNOLOGIE; IMMUNOLOGY; INMUNOLOGIA; Juvenile Hormones - chemistry; Juvenile Hormones - genetics; Juvenile Hormones - metabolism; LATRUNCULIN A; MEMBRANAS CELULARES; MEMBRANE CELLULAIRE; Membranes; MITOSE; MITOSIS; Mother cells; Myristic Acid - metabolism; NEURAL PRECURSOR CELLS; Neurons; ORGANE DES SENS; ORGANOS SENSORIALES; PROTEINAS; PROTEINAS RECOMBINANTES; PROTEINE; PROTEINE RECOMBINANTE; PROTEINS; RECOMBINANT PROTEINS; SENSE ORGANS; SENSORY ORGAN PRECURSORS; SIGNAL PEPTIDE; STRUCTURE CELLULAIRE; SURFACE PROTEINS; Thiazoles - pharmacology; Thiazolidines; TRANSGENIC ANIMALS; Zoology
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.94.24.13005

Drosophila Numb is a membrane associated protein of 557 amino acids (act) that localizes asymmetrically into a cortical crescent in mitotic neural precursor cells and segregates into one of the daughter cells, where it is required for correct cell fate specification. We demonstrate here that asymmetric localization but not membrane localization of Numb in Drosophila embryos is inhibited by latrunculin A, an inhibitor of actin assembly. We also show that deletion of either the first 41 aa or aa 41-118 of Numb eliminates both localization to the cell membrane and asymmetric localization during mitosis, whereas C-terminal deletions or deletions of central portions of Numb do not affect its subcellular localization. Fusion of the first 76 or the first 119 aa of Numb to beta-galactosidase results in a fusion protein that localizes to the cell membrane, but fails to localize asymmetrically during mitosis. In contrast, a fusion protein containing the first 227 aa of Numb and beta-galactosidase localizes asymmetrically during mitosis and segregates into the same daughter cell as the endogenous Numb protein, demonstrating that the first 27 aa of the Numb protein are sufficient for asymmetric localization