KITLG gene

The KITLG gene (KITLG stands for KIT ligand) is a protein-coding gene located on chromosome 12q21.32. This gene encodes the ligand for the receptor-like protein tyrosine kinase KIT.

The encoded protein plays an essential role in the regulation of cell survival and proliferation, hematopoiesis, stem cell maintenance, gametogenesis, mast cell development, migration and function, and melanogenesis. Two transcript variants encoding different isoforms were found for the KITL gene.

KITLG/SCF binding can activate multiple signaling pathways:

• Promotes phosphorylation of PIK3R1, the regulatory subunit of phosphatidylinositol 3-kinase, and subsequent activation of the kinase AKT1.
• KITLG/SCF and KIT also transduce signals through GRB2 and activation of RAS, RAF1, and the MAP kinases MAPK1/ERK2 and/or MAPK3/ERK1.
• KITLG/SCF and KIT promote activation of STAT family members STAT1, STAT3, and STAT5. KITLG/SCF and KIT promote activation of PLCG1, leading to production of the cellular signaling molecules diacylglycerol and inositol 1,4,5-trisphosphate.
• KITLG/SCF acts synergistically with other cytokines, probably interleukins.

Diseases associated with KITLG include "striate and whorl nevoid hypermelanosis" (Sorlin A et al. (2017).

1. Smith MA et al (2001) Stem cell factor: laboratory and clinical aspects. Blood Reviews 15: 191-197.
2. Sorlin A et al (2017) Mosaicism for a KITLG mutation in linear and whorled nevoid hypermelanosis. J Invest Dermatol 137:1575-1578