Adhesive glycoprotein that mediates cell-to-cell and cell-to-matrix interactions ( , ). Multifunctional, involved in inflammation, angiogenesis, wound healing, reactive oxygen species (ROS) signaling, nitrous oxide (NO) signaling, apoptosis, senescence, aging, cellular self-renewal, stemness, and cardiovascular and metabolic homeostasis (   ). Negatively modulates dendritic cell activation and cytokine release, as part of an autocrine feedback loop, contributing to the resolution of inflammation and immune homeostasis . Ligand for receptor CD47 (, ). Modulates nitrous oxide (NO) signaling via CD47, hence playing a role as a pressor agent, supporting blood pressure (By similarity). Plays a role in endothelial cell senescence, acting via CD47, by increasing the abundance and activation of NADPH oxidase NOX1, and so generating excess ROS . Inhibits stem cell self-renewal, acting via CD47 signaling, probably by regulation of the stem cell transcription factors POU5F1/OCT4, SOX2, MYC/c-Myc and KLF4 (By similarity). Negatively modulates wound healing, acting via CD47 (By similarity). Ligand for receptor CD36 ( ). Involved in inducing apoptosis in podocytes in response to elevated free fatty acids, acting via CD36 (By similarity). Plays a role in suppressing angiogenesis, acting, depending on context, via CD36 or CD47 ( , ). Promotes cellular senescence in a TP53-CDKN1A-RB1 signaling-dependent manner . Ligand for immunoglobulin-like cell surface receptor SIRPA . Involved in ROS signaling in non-phagocytic cells, stimulating NADPH oxidase-derived ROS production, acting via interaction with SIRPA . Plays a role in metabolic dysfunction in diet-induced obesity, perhaps acting by exacerbating adipose inflammatory activity; its effects may be mediated, at least in part, through enhanced adipocyte proliferation (By similarity). Plays a role in ER stress response, via its interaction with the activating transcription factor 6 alpha (ATF6) which produces adaptive ER stress response factors (By similarity). May be involved in age-related conditions, including metabolic dysregulation, during normal aging (, ).
Subcellular locations: Secreted, Cell surface, Secreted, Extracellular space, Extracellular matrix, Endoplasmic reticulum, Sarcoplasmic reticulum
Secreted by thrombin-activated platelets and binds to the cell surface in the presence of extracellular Ca(2+) (, ). Incorporated into the extracellular matrix (ECM) of fibroblasts . The C-terminal region in trimeric form is required for retention in the ECM . Also detected in the endoplasmic reticulum and sarcoplasmic reticulum where it plays a role in the ER stress response (By similarity).
Expressed by platelets (at protein level) . Expressed by monocyte-derived immature and mature dendritic cells (at protein level) .