Laminin subunit beta-1

Summary: Laminin subunit beta-1 (LAMB1)

Laminin subunit beta-1 is a major structural component of the extracellular matrix that mediates cell attachment, migration, and tissue organization through high-affinity receptor binding. As a subunit of laminin-1, it plays a crucial role in organizing the laminar architecture of the cerebral cortex and maintains the integrity of the basement membrane/glia limitans, which serves as both an anchor point for radial glial cell endfeet and a physical barrier to neuronal migration during development (UniProt: P07942). The protein is also involved in agrin-induced receptor clustering through a MuSK-independent pathway.

LAMB1 is associated with Lissencephaly 5 (LIS5), an autosomal recessive brain malformation characterized by cobblestone cortical changes, hydrocephalus, seizures, and severely delayed psychomotor development (UniProt: P07942). Mutations disrupting this extracellular matrix protein underscore its essential role in cortical organization.

In Alzheimer's disease, LAMB1 is upregulated in post-mortem AD brain tissue compared to age-matched controls (mean log2 fold-change = 0.80; Chaparral AD proteomics). This elevation may reflect altered basement membrane remodeling or compensatory responses to neurodegeneration and amyloid pathology.