Question

Mac-1, also called CD11b/CD18, is stored in specific granules that are shuttled to the granulocyte surface. It exists as a chemoattractant activation-dependent molecule that undergoes a conformational change upon stimulation. Expression of new epitopes on Mac-1 can be detected after activation using monoclonal antibodies. Antibodies to a subunit of Mac-1 also abrogate granulocyte adhesion to a variety of substrates including fibrinogen, fibronectin, and albumin. Mac-1 belongs to what family of molecules?

Streptolysins
Integrins
Immunophilins
Interleukins
Selectins

Answer 1

Mac-1, or CD11b/CD18, belongs to the (2) integrin family of molecules, which is significant for cell adhesion and the immune response. Integrins are crucial for functions such as phagocytosis and are activated by immune stimuli to bind to various substrates like fibrinogen and fibronectin.

Step-by-step explanation:

Mac-1, also known as CD11b/CD18, is a glycoprotein that plays a crucial role in the immune system. It belongs to the integrin family of molecules. Integrins are transmembrane receptors that are integral to a myriad of biological processes including cell adhesion, cell signaling, and the immune response. Mac-1 is an adhesion molecule that is stored in granulocytes and is responsible for their ability to adhere to various substrates, such as fibrinogen, fibronectin, and albumin.

It is crucial for functions such as phagocytosis, which is the ingestion of bacteria or other material by phagocytes, and is activated by various immune stimuli, which induces a conformational change that allows it to bind more avidly to its ligands. The role of integrins, including Mac-1, becomes apparent in the context of immune response, as they are involved in processes like leukocyte migration and facilitating interactions between cells of the immune system.