Roundabout homolog 1 is a 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...

 that in humans is encoded by the ROBO1 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...

.

Function

Bilateral symmetric nervous systems have special midline structures that establish a partition between the two mirror image halves. Some axon

Axon

An axon is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body or soma....

s project toward and across the midline in response to long-range chemoattractants

Chemotaxis

Chemotaxis is the phenomenon in which somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment. This is important for bacteria to find food by swimming towards the highest concentration of food molecules,...

 emanating from the midline]. In Drosophila

Drosophila

Drosophila is a genus of small flies, belonging to the family Drosophilidae, whose members are often called "fruit flies" or more appropriately pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many species to linger around overripe or rotting fruit...

, the roundabout gene, a member of the immunoglobulin gene superfamily, encodes an integral membrane protein

Integral membrane protein

An integral membrane protein is a protein molecule that is permanently attached to the biological membrane. Proteins that cross the membrane are surrounded by "annular" lipids, which are defined as lipids that are in direct contact with a membrane protein...

 that is both an axon guidance

Axon guidance

Axon guidance is a subfield of neural development concerning the process by which neurons send out axons to reach the correct targets...

 receptor and a cell adhesion

Cell adhesion

Cellular adhesion is the binding of a cell to a surface, extracellular matrix or another cell using cell adhesion molecules such as selectins, integrins, and cadherins. Correct cellular adhesion is essential in maintaining multicellular structure...

 receptor. This receptor is involved in the decision by axons to cross the central nervous system midline. The protein encoded by this gene is structurally similar to the Drosophila roundabout protein. Two transcript variants encoding different isoforms have been found for this gene.

Clinical significance

ROBO1 was implicated in communication disorder based on a Finnish pedigree with severe dyslexia

Dyslexia

Dyslexia is a very broad term defining a learning disability that impairs a person's fluency or comprehension accuracy in being able to read, and which can manifest itself as a difficulty with phonological awareness, phonological decoding, orthographic coding, auditory short-term memory, or rapid...

. Analyses revealed a translocation had occurred disrupting ROBO1. Study of the phonological memory component of the language acquisition system

Language acquisition

Language acquisition is the process by which humans acquire the capacity to perceive, produce and use words to understand and communicate. This capacity involves the picking up of diverse capacities including syntax, phonetics, and an extensive vocabulary. This language might be vocal as with...

suggests that ROBO1 polymorphisms are associated with functioning in this system.