SK-1 or SK1 may refer to:
Sphingosine kinase 1 is an enzyme that in humans is encoded by the SPHK1 gene.
Sphingosine kinase 1 phosphorylates sphingosine to sphingosine-1-phosphate (S1P) SK1 is normally a cytosolic protein but is recruited to membranes rich in phosphatidate (PA), a product of Phospholipase D (PLD)
Sphingosine-1-phosphate (S1P) is a novel lipid messenger with both intracellular and extracellular functions. Intracellularly, it regulates proliferation and survival, and extracellularly, it is a ligand for EDG1. Various stimuli increase cellular levels of S1P by activation of sphingosine kinase (SPHK), the enzyme that catalyzes the phosphorylation of sphingosine. Competitive inhibitors of SPHK block formation of S1P and selectively inhibit cellular proliferation induced by a variety of factors, including platelet-derived growth factor and serum.
SPHK1 has been shown to interact with TRAF2.
Ghaghara, also called Karnali (Nepali: कर्णाली Karṇālī [kʌrˈnɑːliː]; Hindi: घाघरा Ghāghrā [ˈɡʱɑːɡrɑː]) is a perennial trans-boundary river originating on the Tibetan Plateau near Lake Mansarovar. It cuts through the Himalayas in Nepal and joins the Sharda River at Brahmaghat in India. Together they form the Ghaghra River, a major left bank tributary of the Ganges. With a length of 507 kilometres (315 mi) it is the longest river in Nepal. The total length of Ghaghara River up to its confluence with the Ganges at Doriganj in Bihar is 1,080 kilometres (670 mi). It is the largest tributary of the Ganges by volume and the second longest tributary of the Ganges by length after Yamuna.
In Chinese it is called K'ung-ch'iao Ho, in Nepali it is called Kauriala and Karnali. It is also spelled Gogra, Ghaghra, Ghogra, Ghagra, or Ghāghara.
It rises in the southern slopes of the Himalayas in Tibet, in the glaciers of Mapchachungo, at an elevation of about 3,962 metres (12,999 ft) above sea level. The river flows south through one of the most remote and least explored areas of Nepal as the Karnali River. The 202-kilometre (126 mi) Seti River drains the western part of the catchment and joins the Karnali River in Doti District north of Dundras hill. Another tributary, the 264-kilometre (164 mi) long Bheri, rises in the western part of Dhaulagiri Himalaya and drains the eastern part of the catchment, meeting the Karnali near Kuineghat in Surkhet.