An extraovarian protein accumulated in mosquito oocytes is a carboxypeptidase activated in embryos.

TitleAn extraovarian protein accumulated in mosquito oocytes is a carboxypeptidase activated in embryos.
Publication TypeJournal Article
Year of Publication1991
AuthorsCho WL, Deitsch K, Raikhel AS
JournalProc Natl Acad Sci U S A
Volume88
Issue23
Pagination10821-4
Date Published1991 Dec 1
ISSN0027-8424
KeywordsAedes, Amino Acid Sequence, Animals, Base Sequence, Carboxypeptidases, Cloning, Molecular, Embryo, Nonmammalian, Female, Insect Proteins, Isoflurophate, Molecular Sequence Data, Oocytes, Ovary, Polymerase Chain Reaction, Sequence Homology, Nucleic Acid
Abstract

We report a phenomenon previously unknown for oviparous animals; in Aedes aegypti mosquitoes a serine carboxypeptidase is synthesized extraovarially and then internalized by oocytes. The cDNA encoding mosquito vitellogenic carboxypeptidase (VCP) was cloned and sequenced. The VCP cDNA hybridizes to a 1.5-kilobase mRNA present only in the fat body of vitellogenic females. The deduced amino acid sequence of VCP shares significant homology with members of the serine carboxypeptidase family. Binding assays using a serine protease inhibitor, [3H]diisopropyl fluorophosphate, showed that VCP is activated in eggs at the onset of embryonic development. Activation of VCP is associated with the reduction in its size from 53 kDa (inactive proenzyme) to 48 kDa (active enzyme). The active, 48-kDa, form of VCP is maximally present at the middle of embryonic development and disappears by the end.

Alternate JournalProc. Natl. Acad. Sci. U.S.A.
PubMed ID1961751
PubMed Central IDPMC53023

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