Trichohyalin-like protein 1 (TCHHL1)

Trichohyalin-like protein 1 (TCHHL1) is a member of the fused-type S100 protein family characterized by an N-terminal EF-hand calcium-binding domain and association with intermediate filaments[5][3]. TCHHL1 is highly expressed in the basal layer of the epidermis and the inner root sheath of hair follicles, where it participates in skin barrier formation, hair morphogenesis, and regulation of keratinocyte proliferation and survival[1][2][4][7]. Upregulation of TCHHL1 is observed in conditions associated with hyperproliferation of keratinocytes, including psoriasis and squamous cell carcinoma, where it supports tumor cell survival through activation of ERK1/2 and AKT signaling pathways. Targeted reduction of TCHHL1 impairs cell proliferation and enhances apoptosis in both normal and malignant keratinocytes, identifying it as a candidate therapeutic target for proliferative skin diseases[1][2]. Mutations or abnormal expression of TCHHL1 and related S100 fused-type family members are implicated in a spectrum of dermatological conditions[4].

Other names

S100A17THHL1BasalinProtein S100-A17S100 calcium-binding protein A17Trichohyalin-like protein 1Intermediate filament-associated proteinTCHHL1

Not directly targeted by drugs to date; siRNA-mediated knockdown reduces TCHHL1 protein, which results in suppressed cell proliferation and induced apoptosis in keratinocytes and squamous cell carcinoma cells by inhibiting ERK1/2 and AKT phosphorylation and upregulating apoptotic molecules[1][2].