Ras-related protein Rab-23 is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

that in humans is encoded by the ''RAB23''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

. Alternative splicing occurs at this gene locus and two transcript variants encoding the same protein have been identified.

Function

RAB23 belongs to the small

GTPase GTPases are a large family of hydrolase enzymes that bind to the nucleotide guanosine triphosphate (GTP) and hydrolyze it to guanosine diphosphate (GDP). The GTP binding and hydrolysis takes place in the highly conserved P-loop "G domain", a pro ...

superfamily,

Rab Rab �âːb( dlm, Arba, la, Arba, it, Arbe, german: Arbey) is an island in the northern Dalmatia region in Croatia, located just off the northern Croatian coast in the Adriatic Sea. The island is long, has an area of and 9,328 inhabitants (2 ...

family. It may be involved in small GTPase mediated signal transduction and intracellular protein transportation. RAB23 is an essential negative regulator of the

Sonic hedgehog Sonic hedgehog protein (SHH) is encoded for by the ''SHH'' gene. The protein is named after the character ''Sonic the Hedgehog''. This signaling molecule is key in regulating embryonic morphogenesis in all animals. SHH controls organogenesis and ...

signaling pathway. The first understanding of biological processes requiring the Rab23 gene came from 2 independent mouse mutations in the gene and an

epistasis Epistasis is a phenomenon in genetics in which the effect of a gene mutation is dependent on the presence or absence of mutations in one or more other genes, respectively termed modifier genes. In other words, the effect of the mutation is dep ...

analysis with mutations in the mouse shh gene. These studies showed that the gene is required for normal development of the brain and spinal cord and that the morphological defects seen in mutant embryos, such as failure to close dorsal regions of the neural tube during development, appeared secondary to expansion of ventral and reduction of dorsal identities in the developing neural tube. These same mutations implicated the RAB23 gene in development of digits and eyes. The mouse open brain (opb) and Sonic hedgehog (Shh) genes have opposing roles in neural patterning: opb is required for

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal co ...

cell types and Shh is required for

ventral Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Th ...

cell types in the spinal cord.

Function

References

Further reading