Leucine Rich Repeat Proteins: Sequences, Mutations, Structures and Diseases

Area of Science:

• Molecular Biology
• Genetics
• Structural Biology

Background:

• Leucine Rich Repeat (LRR) proteins are implicated in over sixty human diseases, including high myopia, mitochondrial encephalomyopathy, and Crohn's disease.
• Mutations frequently affect the LRR domains, particularly regions shielding the hydrophobic core.
• Published sequences for fifty-five LRR proteins include diverse families like Nod-Like Receptors (NLRs), Small Leucine Rich Repeat Proteoglycans (SLRPs), and F-box/LRR-repeat proteins.

Purpose of the Study:

• To analyze the impact of mutations in Leucine Rich Repeat (LRR) proteins on human health.
• To correlate observed mutations with structural features of LRR domains.
• To understand the functional consequences of these mutations.

Main Methods:

• Analysis of published amino acid sequences for fifty-five LRR proteins.
• Identification and characterization of 363 missense mutations.
• Correlation of mutation types (e.g., amino acid substitutions) with known LRR protein structures.

Main Results:

• Mutations frequently involve amino acid substitutions, particularly affecting arginine, proline, and cysteine residues.
• Observed mutations impact critical protein properties including folding, aggregation, oligomerization, stability, and disulfide bond formation.
• The majority of mutations result in a loss of protein function, with a few instances of gain of function.

Conclusions:

• Mutations in LRR-encoding genes are a significant cause of human disease.
• Understanding the structural basis of these mutations is crucial for predicting their functional impact.
• These findings highlight the importance of LRR proteins in cellular processes and disease pathogenesis.