An IQGAP-related gene is activated during tentacle formation in the simple metazoan Hydra.
Differentiation of body column epithelial cells into tentacle epithelial cells in Hydra is accompanied by changes in both cell shape and cell-cell contact. The molecular mechanism by which epithelial cells acquire tentacle cell characteristics is unknown. Here we report that expression of a Hydra homologue of the mammalian IQGAP1 protein is strongly upregulated during tentacle formation. Like mammalian IQGAP, Hydra IQGAP1 contains an N-terminal calponin-homology domain, IQ repeats and a conserved C terminus. In adult polyps a high level of Hydra IQGAP1 mRNA is detected at the basis of tentacles. Consistent with a role in tentacle formation, IQGAP1 expression is activated during head regeneration and budding at a time when tentacles are emerging. The observations support the previous hypothesis that IQGAP proteins are involved in cytoskeletal as well as cell-cell contact rearrangements.
Venturelli
C R
CR
CINVESTAV-IPN, Dept. Genetica, 07000 Mexico.
Kuznetsov
S
S
Salgado
L M
LM
Bosch
T C
TC
D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary; D006829:Hydra / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012038:Regeneration; D017386:Sequence Homology, Amino Acid; D020703:ras GTPase-Activating Proteins
D002352:Carrier Proteins; D018076:DNA, Complementary; C101203:IQ motif containing GTPase activating protein 1; D020703:ras GTPase-Activating Proteins