HAPLN3

HAPLN3, or hyaluronan and proteoglycan link protein 3, is a protein encoded by the HAPLN3 gene in humans. It belongs to the hyaluronan and proteoglycan linkage protein (HAPLN) family, which stabilizes the extracellular matrix (ECM) by coordinating hyaluronan with proteoglycans such as aggrecan, brevican, neurocan, and versican.

HAPLN3, like other HAPLN family members, is secreted into the extracellular matrix and functions to promote the formation of large HA-proteoglycan aggregates that contribute to ECM integrity and tissue mechanical properties.

Expression and distribution: Studies indicate HAPLN3 transcripts are detected in multiple tissues, with higher levels reported in brain and reproductive tissues in some analyses; however, exact expression patterns vary among species and datasets; overall, the tissue distribution is less well defined than for HAPLN1.

Structure and interactions: The protein is predicted to be secreted and binds HA and proteoglycans to form ternary complexes linking HA to proteoglycans at ECM interfaces.

Clinical relevance: There are relatively few reports on HAPLN3-specific disease associations; ongoing research investigates its potential roles in development, neural ECM organization, and cancer where ECM remodeling plays a role.