Mitogen-activated protein kinase kinase kinase 5

MAP3K5 (also known as ASK1) is a serine/threonine kinase that functions as a critical node in mitogen-activated protein kinase signal transduction. It acts as an upstream activator of the JNK and p38 MAPK cascades through phosphorylation of MAP2K family members, thereby controlling cellular responses to environmental stress, differentiation, survival, and apoptosis (UniProt: Q99683).

The protein mediates signaling in response to oxidative stress and inflammatory signals including TNF and lipopolysaccharide, and is essential for innate immune responses. These functions position MAP3K5 at the intersection of stress-response and apoptotic pathways with relevance to neuroinflammation and cell death mechanisms.

MAP3K5 is upregulated in Alzheimer's Disease brain tissue relative to age-matched controls (mean log2FC = 0.23, Chaparral AD proteomics), suggesting enhanced activation of stress-responsive and apoptotic signaling cascades in the AD brain. This elevation aligns with the pathobiological role of MAP3K5 in mediating cellular responses to the oxidative stress and inflammatory insults characteristic of AD neurodegeneration.