LTK

Receptor with a tyrosine-protein kinase activity (PubMed:10445845, PubMed:20548102, PubMed:30061385). Following activation by ALKAL1 or ALKAL2 ligands at the cell surface, transduces an extracellular signal into an intracellular response (PubMed:30061385, PubMed:34646012). Ligand-binding to the extracellular domain induces tyrosine kinase activation, leading to activation of the mitogen-activated protein kinase (MAPK) pathway (PubMed:20548102). Phosphorylates almost exclusively at the first tyrosine of the Y-x-x-x-Y-Y motif (By similarity). The exact function of this protein is not known; studies with chimeric proteins demonstrate its ability to promote growth and specifically neurite outgrowth, and cell survival (PubMed:18849880, PubMed:9223670). Involved in regulation of the secretory pathway involving endoplasmic reticulum (ER) export sites (ERESs) and ER to Golgi transport (PubMed:20548102).

Genetic variations in LTK that cause up-regulation of the PI3K pathway may possibly contribute to susceptibility to abnormal proliferation of self-reactive B-cells and, therefore, to systemic lupus erythematosus (SLE) (PubMed:14695357). SLE is a chronic, inflammatory and often febrile multisystemic disorder of connective tissue, thought to represent a failure of the regulatory mechanisms of the autoimmune system (PubMed:14695357).

Phosphorylated at tyrosine residues by autocatalysis, which activates kinase activity.

Belongs to the protein kinase superfamily. Tyr protein kinase family. Insulin receptor subfamily.

Expressed in non-hematopoietic cell lines and T- and B-cell lines.

• Cell membrane
• Single-pass type I membrane protein

TYK1, LTK, Leukocyte tyrosine kinase receptor, Protein tyrosine kinase 1

• entrezGene:4058
• omim:151520
• swissprot:P29376

Proteins

Immunology & Infectious Disease

91681Da