Genomic analysis of C-type lectins.

Area of Science:

• Biochemistry
• Molecular Biology
• Evolutionary Biology

Background:

• Complex carbohydrates mediate biological effects via lectins with carbohydrate-recognition domains.
• Seven distinct lectin families are involved in crucial cellular processes like trafficking, adhesion, signaling, and immunity.
• Genome-wide analysis enables comprehensive study of carbohydrate-binding domains.

Purpose of the Study:

• To propose an overall picture of lectins present in humans.
• To suggest ligand-binding activity for novel C-type lectin-like domains.
• To provide a basis for proposing potential biological functions of identified lectin domains.

Main Methods:

• Genome-wide analysis of potential carbohydrate-binding domains.
• Comparative analysis of lectin classes across species (yeast, invertebrates, vertebrates).
• Structural knowledge of C-type carbohydrate-recognition domains to infer function.

Main Results:

• Two intracellular lectin classes are conserved across yeast and vertebrates; two others are vertebrate-specific.
• Cell-surface lectins (C-type, galectins) are found in invertebrates and vertebrates, while I-type lectins are vertebrate-specific.
• Novel C-type lectin-like domains were identified in a human genome screen.

Conclusions:

• The evolutionary emergence of lectin classes correlates with oligosaccharide complexity.
• Ligand-binding activities can be proposed for novel C-type lectin-like domains based on structural similarities.
• Sequence analysis of proteins with these domains can predict their biological functions.