Sphingomyelin phosphodiesterase (IPR011160)

Short name: Sphingomy_PDE

Overlapping homologous superfamilies


Family relationships



Sphingomyelin phosphodiesterase, or sphingomyelinase (SMase), enzymes catalyse the hydrolysis of sphingomyelin into ceramide (N-acylsphingosine) and phosphorylcholine. There are six types of SMases: acid SMase, secretory SMase, neutral magnesium-dependent SMase, neutral magnesium-independent SMase, alkaline SMase, and bacterial SMase [PMID: 12401200]. This entry covers the acid SMases.

Sphingomyelin is a ubiquitous lipid found in plasma membranes, as well in lipoproteins; in mammalian cells, it is the most abundant sphingolipid. Sphingoid molecules generated from the breakdown of sphingolipids can act as intracellular bio-modulators. In particular, ceramide can act as a second messenger in diverse signalling pathways leading to different cellular responses, such as apoptosis [PMID: 12531545]. Hence, SMase activation can be an early event in the apoptosis-signalling cascade. SMase is regulated by several mechanisms, including tumour necrosis factor (TNF) receptor-associated protein FAN (Factor Associated with N-sphingomyelinase activation) and oxidative stress.

GO terms

Biological Process

GO:0006685 sphingomyelin catabolic process

Molecular Function

GO:0004767 sphingomyelin phosphodiesterase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.