Introduction:

• Part of annexin protein group
• Binds to phospholipids in calcium-dependent manner
• 33kDa protein
• Important in cellular functions
• Serves as target and biomarker

Structure and Molecular Properties:

• Contains four similar repeats (~70 amino acids each)
• Has distinctive N-terminal section
• Central domain contains calcium binding spots
• N-terminal facilitates protein interactions
• Undergoes post-translational modifications

Physiological Functions and Cellular Regulation:

• Regulates:
• Membrane traffic flow
• Cell signaling
• Exocytosis
• Involved in:
• Cellular stress response
• Immune cell function
• Inflammation
• Cytoskeleton organization
• Cell differentiation
• Proliferation
• Autophagy
• Apoptotic processes

Role in Disease Pathogenesis:

• Cancer:
• Elevated in liver, pancreatic, lung cancers
• Correlates with poor prognosis
• Enhances tumor cell proliferation
• Increases metastatic potential
• Contributes to drug resistance
• Promotes angiogenesis
• Inflammatory Disorders:
• Associated with arthritis
• Linked to inflammatory bowel disease
• Affects neutrophil movement/activation

Clinical Applications and Future Perspectives:

• Diagnostic Biomarker:
• Shows differential expression
• Indicates disease progression
• Monitors treatment response
• Therapeutic Target:
• Development of specific inhibitors
• Combination therapy approaches
• Novel drug delivery systems