Laminin and fibronectin are involved in all the following cell function except –
**Core Concept**
Laminin and fibronectin are two major components of the extracellular matrix that play crucial roles in cell adhesion, migration, and differentiation. They interact with integrins on the cell surface, triggering signaling pathways that regulate various cellular functions.
**Why the Correct Answer is Right**
Fibronectin and laminin are essential for cell adhesion, as they provide a physical link between cells and the extracellular matrix. They also facilitate cell migration by interacting with integrins and other receptors, which triggers signaling pathways involved in cell movement and tissue repair. Additionally, these proteins are involved in cell differentiation, influencing the development and maintenance of various cell types.
**Why Each Wrong Option is Incorrect**
**Option A:** Cell proliferation - While laminin and fibronectin can influence cell growth indirectly by regulating cell adhesion and migration, they are not directly involved in cell proliferation.
**Option B:** Angiogenesis - Fibronectin and laminin can influence angiogenesis by providing a scaffold for endothelial cell migration and tube formation, but this is not their primary function.
**Option C:** Collagen synthesis - Laminin and fibronectin interact with collagen and other extracellular matrix components, but they do not regulate collagen synthesis directly.
**Clinical Pearl / High-Yield Fact**
Remember that laminin and fibronectin are crucial for maintaining tissue integrity and facilitating wound healing. Deficiencies in these proteins can lead to various diseases, including epidermolysis bullosa and muscular dystrophy.
**Correct Answer: A. Cell proliferation**