What is the consequence of a loss-of-function mutation in phospholipase C in terms of cell junctions?

What is the consequence of a loss-of-function mutation in phospholipase C in terms of cell junctions?

• A. Apical membrane proteins can easily diffuse to the basolateral membrane
• B. The tight junctions will strengthen
• C. Phosphatidylinositol PIP2 will be overproduced
• D. Cell communication will enhance

Answer: (A)

A loss-of-function mutation in phospholipase C would lead to a breakdown of certain cellular signaling pathways that depend on the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) to produce inositol trisphosphate (IP3) and diacylglycerol (DAG). This signaling is crucial for maintaining various cellular processes, including the integrity of cell junctions. When tight junctions are compromised as a result of this mutation, the normally controlled interactions between the apical and basolateral membranes become disrupted. As a consequence, proteins that are meant to be retained in the apical membrane can start to diffuse more freely to the basolateral membrane, leading to a loss of polarity in the epithelial cells. This indicates that the loss of function in phospholipase C negatively impacts cell adhesion, resulting in altered distributions of membrane proteins. While the other options might suggest some responses to altered phospholipase C function, they do not accurately encompass the central issue that arises from its loss-of-function mutation, particularly in terms of junctional integrity and membrane protein distribution.

A loss-of-function mutation in phospholipase C would lead to a breakdown of certain cellular signaling pathways that depend on the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) to produce inositol trisphosphate (IP3) and diacylglycerol (DAG). This signaling is crucial for maintaining various cellular processes, including the integrity of cell junctions.

When tight junctions are compromised as a result of this mutation, the normally controlled interactions between the apical and basolateral membranes become disrupted. As a consequence, proteins that are meant to be retained in the apical membrane can start to diffuse more freely to the basolateral membrane, leading to a loss of polarity in the epithelial cells. This indicates that the loss of function in phospholipase C negatively impacts cell adhesion, resulting in altered distributions of membrane proteins.

While the other options might suggest some responses to altered phospholipase C function, they do not accurately encompass the central issue that arises from its loss-of-function mutation, particularly in terms of junctional integrity and membrane protein distribution.