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CTSB

Function

Thiol protease which is believed to participate in intracellular degradation and turnover of proteins (PubMed:12220505). Cleaves matrix extracellular phosphoglycoprotein MEPE (PubMed:12220505). Involved in the solubilization of cross-linked TG/thyroglobulin in the thyroid follicle lumen (By similarity). Has also been implicated in tumor invasion and metastasis (PubMed:3972105).

Involvement in disease

Keratolytic winter erythema

KWE

An autosomal dominant genodermatosis characterized by recurrent episodes of palmoplantar erythema and epidermal peeling presenting seasonal variation. KWE manifests during childhood. Skin lesions may spread to the dorsum of hands and feet and to the interdigital spaces. Lower legs, knees and thighs may also be involved. A less common finding is a slowly migratory, annular erythema that is seen mostly on the extremities. Between flares, the skin can appear unremarkable. Itching can occur, and hyperhidrosis, associated with a pungent odor, is invariably present. Formation of vesicles is rare, whereas keratolysis that causes the formation of dry blisters is regularly seen. Cold weather, moisture, febrile diseases, and physical and mental stress can trigger exacerbations. In severely affected individuals, skin manifestations persist unremittingly. Penetrance of the disease is high, but expressivity is variable, even within the same family.

None

The gene represented in this entry is involved in disease pathogenesis. Tandem duplications in a non-coding genomic region containing an active enhancer element for CTSB result in CTSB abnormal expression with pathological consequences.

Sequence similarities

Belongs to the peptidase C1 family.

Tissue specificity

Expressed in the stratum spinosum of the epidermis. Weak expression is detected in the stratum granulosum.

Cellular localization

  • Lysosome
  • Melanosome
  • Secreted
  • Extracellular space
  • Apical cell membrane
  • Peripheral membrane protein
  • Extracellular side
  • Identified by mass spectrometry in melanosome fractions from stage I to stage IV (PubMed:17081065). Localizes to the lumen of thyroid follicles and to the apical membrane of thyroid epithelial cells (By similarity).

Alternative names

  • Cathepsin B
  • APP secretase
  • Cathepsin B1
  • APPS
  • CTSB
  • CPSB

Target type

Proteins

Primary research area

Neuroscience

Molecular weight

37822Da