Lumican

Ideogram human chromosome 12

Lumican

Lumican is a protein that in humans is encoded by the LUM gene. It is a member of the small leucine-rich proteoglycan (SLRP) family. Lumican is a key component of the extracellular matrix in various tissues, including the cornea, skin, and heart.

Structure

Lumican consists of a core protein with attached glycosaminoglycan chains. It contains leucine-rich repeats that are involved in protein-protein interactions and binding to other extracellular matrix components.

Function

Lumican plays a crucial role in regulating collagen fibril assembly and organization. It interacts with collagen fibers, contributing to the structural integrity and mechanical properties of tissues. Additionally, lumican has been implicated in cell adhesion, migration, and proliferation processes.

Clinical Significance

Mutations in the LUM gene can lead to various connective tissue disorders, affecting the integrity of tissues where lumican is abundant. Deficiencies in lumican have been associated with corneal dystrophies and skin abnormalities.

Role in the Cornea

In the cornea, lumican is essential for maintaining transparency and proper refractive properties. It interacts with collagen fibrils to ensure the cornea's structural stability and optical clarity.

Role in the Skin

In the skin, lumican contributes to the organization of collagen fibers, influencing the skin's elasticity and strength. Alterations in lumican levels can impact skin aging and wound healing processes.

Role in the Heart

Lumican is also present in the heart, where it modulates the extracellular matrix composition and cardiac function. Changes in lumican expression have been linked to cardiac fibrosis and remodeling.