Question

Which of the following is true of the Gram-positive model for quorum sensing activation of gene expression?

A. The binding of a short peptide autoinducer to a membrane-bound kinase sensor leads to phosphorylation of a response regulator protein, which activates target gene expression
B. The binding of an AHL autoinducer to a membrane-bound kinase sensor leads to phosphorylation of a response regulator protein, which activates target gene expression
C. The binding of an AHL autoinducer to a cytoplasmic kinase sensor leads to phosphorylation of a response regulator protein, which activates target gene expression
D. The binding of a short peptide autoinducer to a cytoplasmic kinase sensor leads to phosphorylation of a response regulator protein, which activates target gene expression

Answer 1

The correct statement on Gram-positive bacteria's quorum sensing is that a short peptide autoinducer binds to a membrane-bound kinase sensor and leads to phosphorylation of a response regulator protein, activating gene expression.

Step-by-step explanation:

The true statement about the Gram-positive model for quorum sensing activation of gene expression is: A. The binding of a short peptide autoinducer to a membrane-bound kinase sensor leads to phosphorylation of a response regulator protein, which activates target gene expression.

This process starts with the autoinducer binding to its receptor only when a threshold concentration of signaling molecules is reached. In Gram-positive bacteria, the autoinducer is typically a short peptide that interacts with a membrane-bound kinase sensor.

This interaction then leads to a cascade of signaling events, including the phosphorylation of a response regulator, which in turn activates the gene expression linked to quorum sensing responses such as biofilm formation and the production of virulence factors.