SPRY4

SPRY4 is a protein-coding gene in humans that encodes Sprouty-related protein 4, a member of the Sprouty family of intracellular regulators of receptor tyrosine kinase signaling. Sprouty proteins generally function as negative feedback inhibitors of signaling pathways activated by growth factors, helping to shape cellular responses during development and tissue homeostasis. SPRY4 is thought to dampen signaling from several receptor tyrosine kinases, most notably the fibroblast growth factor receptor (FGFR) and epidermal growth factor receptor (EGFR) pathways, by interfering with downstream components of the Ras–MAPK cascade; the precise mechanism may involve disruption of adaptor protein complex formation or recruitment of inhibitory factors at the receptor or cytoplasmic level. The protein is cytoplasmic and is expressed in multiple tissues, with expression patterns that suggest roles in development and cellular differentiation.

The SPRY4 gene locus also produces noncoding transcripts, including SPRY4-IT1, a long noncoding RNA transcribed from the SPRY4 locus that has been studied in various cellular contexts and may influence gene expression regulation and cellular behavior.

Clinical significance: Altered SPRY4 expression or function has been investigated in relation to cancer and developmental disorders, reflecting the broader role of Sprouty family proteins in controlling growth factor–driven signaling. However, as with other components of RTK signaling networks, the effects of SPRY4 dysregulation are context dependent and not fully understood.