Two forms of human Inscuteable-related protein that links Par3 to the Pins homologues LGN and AGS3.
In cell polarization of Drosophila neuroblasts, Inscuteable (Insc) functions via tethering Partner of Insc (Pins) to Bazooka, homologous to human cell polarity protein Par3. However, little has been known about mammalian homologues of Insc. Here we describe cloning of two distinct cDNAs from human Insc gene, which is differentially expressed from alternative first exons: one encodes 579 amino acids, whereas the other lacks the N-terminal 47 amino acids. In contrast to human homologues for Pins and Par3, human Insc exhibits a weak homology with the Drosophila counterpart. Nevertheless, human Insc proteins bind to the human Pins homologues LGN and AGS3, and also to human Par3 and its related protein Par3beta. Although LGN by itself is incapable of interacting with Par3, coexpression of human Insc leads to the interaction between LGN and Par3, indicating that human Insc plays an evolutionarily conserved role as an adaptor protein that links Pins to Par3.
Izaki
Tomoko
T
Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Kamakura
Sachiko
S
Kohjima
Motoyuki
M
Sumimoto
Hideki
H
D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D016764:Cell Polarity / Q000502:physiology; D004331:Drosophila melanogaster; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D014018:Tissue Distribution
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C102754:GPSM2 protein, human; C509688:INSC protein, human; C509689:PARD3 protein, human; C471157:PARD3B protein, human