Of ITIM s, ITAM s, and ITAM is: revisiting immunoglobulin Fc receptor signaling

A Getahun, JC Cambier - Immunological reviews, 2015 - Wiley Online Library
A Getahun, JC Cambier
Immunological reviews, 2015Wiley Online Library
Receptors for immunoglobulin Fc regions play multiple critical roles in the immune system,
mediating functions as diverse as phagocytosis, triggering degranulation of basophils and
mast cells, promoting immunoglobulin class switching, and preventing excessive activation.
Transmembrane signaling associated with these functions is mediated primarily by two
amino acid sequence motifs, ITAM s (immunoreceptor tyrosine‐based activation motifs) and
ITIM s (immunoreceptor tyrosine‐based inhibition motifs) that act as the receptors' interface …
Summary
Receptors for immunoglobulin Fc regions play multiple critical roles in the immune system, mediating functions as diverse as phagocytosis, triggering degranulation of basophils and mast cells, promoting immunoglobulin class switching, and preventing excessive activation. Transmembrane signaling associated with these functions is mediated primarily by two amino acid sequence motifs, ITAMs (immunoreceptor tyrosine‐based activation motifs) and ITIMs (immunoreceptor tyrosine‐based inhibition motifs) that act as the receptors’ interface with activating and inhibitory signaling pathways, respectively. While ITAMs mobilize activating tyrosine kinases and their consorts, ITIMs mobilize opposing tyrosine and inositol‐lipid phosphatases. In this review, we will discuss our current understanding of signaling by these receptors/motifs and their sometimes blurred lines of function.
Wiley Online Library