Mutational Analysis of the Drosophila Snake Protease: An Essential Role for Domains within the Proenzyme Polypeptide Chain
AUTOR(ES)
Smith, C.
RESUMO
Two genes involved in the generation of dorsoventral asymmetry in the developing Drosophila melanogaster embryo, snake and easter, encode the zymogen form of serine proteases. Mutant alleles of snake were cloned and sequenced revealing two types of lesions: point mutations which alter the amino acid sequence (snk(073) and snk(rm4)) and point mutations which alter the splicing (snk(229) or snk(233)) of intron 1 of the mRNA from the normal 3' end of the intron to a cryptic site. snake mutant embryos derived from homozygous mothers can be fully rescued by injection of RNA transcripts of the wild-type snake cDNA. RNA phenotypic rescue and site-directed mutagenesis experiments indicate that snake requires the serine, histidine and aspartic acid of the catalytic triad for normal activity. Deletion experiments show that an acidic proenzyme domain is required for snake rescue activity to be uniformly distributed throughout the embryo. A second proenzyme domain, called the disulfide knot, appears to be essential for normal regulation of activity of the snake catalytic chain. Transcripts encoding only the proenzyme polypeptides of either snake or easter can dorsalize wild type embryos. We propose a model in which the proenzyme determinants of both the snake and easter enzymes mediate interaction between the serine proteases and other components of the dorsal-ventral patterning system.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1205916Documentos Relacionados
- Separate functional domains of the herpes simplex virus type 1 protease: evidence for cleavage inside capsids.
- EcfE, a new essential inner membrane protease: its role in the regulation of heat shock response in Escherichia coli
- Light-stimulated degradation of an unassembled Rieske FeS protein by a thylakoid-bound protease: the possible role of the FtsH protease.
- Mutational analysis of an archaebacterial promoter: essential role of a TATA box for transcription efficiency and start-site selection in vitro.
- Mutational analysis of the Vibrio fischeri LuxI polypeptide: critical regions of an autoinducer synthase.