Protein kinase LYK5, also known as LYK5 or STRADα, is a human protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 and also denotes the gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

 encoding it.

Function

Endogenous LKB1

STK11

Serine/threonine kinase 11 also known as liver kinase B1 or renal carcinoma antigen NY-REN-19 is a protein kinase that in humans is encoded by the STK11 gene.-Expression:...

 and STRADα form a complex in which STRADα activates LKB1, resulting in phosphorylation

Phosphorylation

Phosphorylation is the addition of a phosphate group to a protein or other organic molecule. Phosphorylation activates or deactivates many protein enzymes....

 of both partners. Removal of endogenous LYK5 by small interfering RNA

Small interfering RNA

Small interfering RNA , sometimes known as short interfering RNA or silencing RNA, is a class of double-stranded RNA molecules, 20-25 nucleotides in length, that play a variety of roles in biology. The most notable role of siRNA is its involvement in the RNA interference pathway, where it...

 abrogates LKB1-induced G1 phase

G1 phase

The G1 phase is a period in the cell cycle during interphase, before the S phase. For many cells, this phase is the major period of cell growth during its lifespan. During this stage new organelles are being synthesized, so the cell requires both structural proteins and enzymes, resulting in great...

 arrest.

Disease linkage

Mutations in the LYK5/STRADα gene are associated with polyhydramnios

Polyhydramnios

Polyhydramnios is a medical condition describing an excess of amniotic fluid in the amniotic sac. It is seen in 0.2 to 1.6% of pregnancies,,...

, megalencephaly

Megalencephaly

Megalencephaly is a condition in which there is an abnormally large brain. It is usually functioning abnormally. Megalencephaly is, by definition, when the brain weight is greater than average for the age and sex of the infant or child...

 and symptomatic epilepsy

Epilepsy

Epilepsy is a common chronic neurological disorder characterized by seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain.About 50 million people worldwide have epilepsy, and nearly two out of every three new cases...

 (collectively known as the PMSE syndrome).

Interactions

STRADα has been shown to interact

Protein-protein interaction

Protein–protein interactions occur when two or more proteins bind together, often to carry out their biological function. Many of the most important molecular processes in the cell such as DNA replication are carried out by large molecular machines that are built from a large number of protein...

 with LKB1 and MO25.

Further reading