Structural requirements for the tissue-specific and tissue-general functions of the Caenorhabditis elegans epidermal growth factor LIN-3.
Caenorhabditis elegans lin-3 encodes a homolog of the epidermal growth factor (EGF) family of growth factors. LIN-3 is the inductive signal for hermaphrodite vulval differentiation, and it is required for animal viability, hermaphrodite fertility, and the specification of anterior cell fates in the male B cell lineage. We describe the cloning of a lin-3 homolog from C. briggsae, sequence comparison of C. elegans lin-3 with C. briggsae lin-3, and the determination of molecular lesions in alleles of C. elegans lin-3, including three new alleles. We also analyzed the severity of phenotypes caused by the new and existing alleles of lin-3. Correlation of mutant phenotypes and their molecular lesions, as well as sequence comparison between two species, reveal that the EGF motif and the N-terminal portion of the cytoplasmic domain are important for the functions of LIN-3 in all tissues, while the C-terminal portion of the cytoplasmic domain is involved in the tissue-specific functions of lin-3. We discuss how the structure of lin-3 contributes to its functions in multiple developmental processes.
Liu
J
J
Howard Hughes Medical Institute and Division of Biology, California Institute of Technology, Pasadena, California 91125, USA.
Tzou
P
P
Hill
R J
RJ
Sternberg
P W
PW
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D002107:Caenorhabditis / Q000235:genetics; D017173:Caenorhabditis elegans / Q000235:genetics / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins; D017124:Conserved Sequence; D012734:Disorders of Sex Development; D004815:Epidermal Growth Factor / Q000502:physiology; D005091:Exons; D005260:Female; D005298:Fertility; D005804:Genes, Lethal; D015801:Helminth Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology*; D008297:Male; D008969:Molecular Sequence Data; D010641:Phenotype; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D017385:Sequence Homology; D013489:Suppression, Genetic; D014844:Vulva / Q000502:physiology
D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins; C075912:Lin-3 protein, C elegans; D004815:Epidermal Growth Factor