Functions of S100 proteins

Area of Science:

• Biochemistry
• Cell Biology
• Immunology

Background:

• The S100 protein family comprises 24 members with diverse intracellular and extracellular functions.
• S100 proteins exhibit cell-specific expression in vertebrates and can be induced under pathological conditions.
• They play roles in cell proliferation, differentiation, apoptosis, Ca2+ homeostasis, metabolism, and inflammation.

Purpose of the Study:

• To elucidate the multifaceted roles of S100 proteins in cellular regulation and extracellular signaling.
• To highlight the involvement of S100 proteins in both normal physiological and pathological conditions.
• To detail the interactions of S100 proteins with various cellular targets and surface receptors.

Main Methods:

• Analysis of S100 protein family structure and function.
• Investigation of intracellular interactions with enzymes, cytoskeletal proteins, transcription factors, and nucleic acids.
• Examination of extracellular signaling via receptor activation (e.g., RAGE, TLR4) and interactions with growth factors.

Main Results:

• S100 proteins regulate intracellular processes including proliferation, apoptosis, and metabolism.
• Extracellular S100 proteins modulate cell functions through autocrine and paracrine signaling via multiple receptor types.
• Specific S100 proteins (S100A4, S100B) enhance growth factor receptor activity.
• Extracellular S100 proteins influence a wide range of cell types, impacting immune responses, cell migration, and tissue repair.

Conclusions:

• S100 proteins are key regulators of cellular functions and intercellular communication in vertebrates.
• Their dual intracellular and extracellular activities are critical for immune responses, cell migration, and tissue homeostasis.
• Dysregulation of S100 proteins may contribute to pathological conditions, highlighting their therapeutic potential.