Programmed Trade-offs in Protein Folding Networks.

Area of Science:

• Molecular biology
• Protein homeostasis
• Biochemistry

Background:

• Molecular chaperones are crucial for maintaining cellular protein quality control and homeostasis.
• Understanding how chaperones selectively bind substrate proteins is key to understanding their limited capacity.
• The Saccharomyces cerevisiae Hsp70 Ssb chaperone's substrate interactions are not fully understood.

Purpose of the Study:

• To analyze sequence and structural determinants of protein domain interactions with Saccharomyces cerevisiae Hsp70 Ssb.
• To investigate the relationship between protein folding landscapes, codon usage, and chaperone interactions.

Main Methods:

• Integrated analysis of sequence and structural data for protein domains.
• Comparison of folding landscapes, nonoptimal codon usage, and sequence features in Ssb-interacting proteins.
• Identification of discriminative sequences influencing chaperone interactions.

Main Results:

• Proteins interacting differently with Ssb exhibited variations in folding landscape complexity and codon usage.
• Short discriminative sequences were identified as the strongest predictors of Ssb interactions.
• Chaperone interactions appear to be directly programmed in amino acid sequences.

Conclusions:

• Protein folding landscapes and sequence features, particularly short discriminative sequences, dictate interactions with molecular chaperones like Ssb.
• Direct programming of chaperone interactions via amino acid sequences may offer regulatory advantages.
• This study reveals trade-offs in chaperone-assisted protein folding and highlights sequence-based regulation.