Deep research providers are unavailable here (just deep-research-falcon fails with
"agentapi not found in PATH"; perplexity is not configured). Notes are from the cached
publication, the UniProt record and PubMed.
Desmoglein-4 is the fourth desmosomal cadherin, a single-pass type I membrane
glycoprotein with calcium-binding extracellular cadherin domains and a cytoplasmic tail
that binds plakoglobin (JUP). Unlike DSG1 and DSG3, its expression is concentrated in
the hair follicle — inner root sheath, matrix and precortex — with lower expression in
other epithelia.
[file:human/DSG4/DSG4-uniprot.txt "In scalp follicles, present in the inner root sheath (IRS) and all layers of the matrix and precortex (at protein level)"]
Compound heterozygous DSG4 mutations cause autosomal recessive monilethrix; the W823X
mutant loses affinity for plakoglobin, implicating DSG4-plakoglobin coupling in
desmosome integrity in the hair shaft.
PMID:21495994
UniProt records the interaction and the colocalization.
[file:human/DSG4/DSG4-uniprot.txt "Note=Colocalizes with JUP at desmosomes."]
Localization conclusion: plasma membrane and desmosome, cadherin ectodomain
extracellular. The cornified-envelope rows derive from Reactome cornification pathway
membership and an ARBA rule, not from a DSG4 localization experiment, and DSG4 protein
is documented in the follicle rather than in the cornified layer.
Lymphocyte-migration rows come from rodent orthologs (rat Q6W3B0, mouse Q7TMD7) and are
recorded by UniProt only "By similarity"; they are kept as non-core.