Overview:

VLK or vertebrate lonesome kinase is a protein kinase which is first expressed in E-cadherin-positive anterior visceral endoderm and mesendoderm, and later its expression is confined to E-cadherin-negative mesenchyme. VLK regulates the rate of protein export from the Golgi and thereby plays an important role in the formation of functional stroma by mesenchymal cells (1). Targeted disruption of VLK leads to a defect in lung development and delayed ossification of endochondral bone. VLK deficient mice display neonatal lethality due to respiratory failure, with a suckling defect arising from a cleft palate. VLK is required for the appropriate timing of flat proliferative chondrocyte differentiation (2).

References:

1. Kinoshita. et.al: The novel protein kinase Vlk is essential for stromal function of mesenchymal cells.Development 136: 2069-2079, 2009.

2. Imuta, Y. et al: Short limbs, cleft palate, and delayed formation of flat proliferative chondrocytes in mice with targeted disruption of a putative protein kinase gene, Pkdcc (AW548124). Dev Dyn. 2009 Jan; 238(1):210-22.