Accession Number : ADA194800

Title :   Secretory Polypeptides Encoded in Balbiani Ring Genes.

Descriptive Note : Annual rept. 15 Apr 87-14 Apr 88,

Corporate Author : MISSISSIPPI UNIV MEDICAL CENTER JACKSON DEPT OF BIOCHEMISTRY

Personal Author(s) : Case, Steven T

PDF Url : ADA194800

Report Date : 28 Apr 1988

Pagination or Media Count : 7

Abstract : The aim of this project is to learn about the structure, developmentally regulated synthesis and assembly of a family of secretory polypeptides (SPs) into an insoluble polymer of silk-like threads. SPs are exclusively synthesized in salivary glands of aquatic larvae of the Dipteran, Chironomus. All Sps studied to date are composed of tandemly repeated amino acid sequences. Recombinant cDNA probes are used to map SP-coding genes on polytene chromosomes, identify their mRNAs on Northern blots and derive the amino acid sequence of their encoded polypeptide. cDNA probes and anti-SP antibodies are used to study the level at which SP gene regulation occurs during normal larval development and under conditions of galactose-induced alterations in gene expression. SP assembly in vitro is being studied by a combination of physical, electron microscopic and biochemical methods. We hope to learn which SPs interact with each other and what is the chemical nature of these interactions. We eventually plan to determine the spatial distribution of SPs within assembled complexes by making three-dimensional tomographci reconstructions from immunoelectron micrographs. This experimental system provides a unique opportunity to study how naturally occurring soluble polypeptides can assemble into an insoluble fiber that functions in an aqueous environment.

Descriptors :   *AMINO ACIDS, *PEPTIDES, ASSEMBLY, BIOCHEMISTRY, CHROMOSOMES, ELECTRON MICROSCOPY, ELECTRONS, ENVIRONMENTS, GENES, IN VITRO ANALYSIS, LARVAE, LIQUIDS, POLYMERS, SALIVARY GLANDS, SECRETION, SEQUENCES, SOLUBILITY, SPATIAL DISTRIBUTION, MOLECULE MOLECULE INTERACTIONS, DIPTERA, BIOSYNTHESIS

Subject Categories : Genetic Engineering and Molecular Biology

Distribution Statement : APPROVED FOR PUBLIC RELEASE