Rnd3

Rnd3 is a small (~21 kDa) signaling G protein (to be specific, a GTPase), and is a member of the Rnd subgroup of the Rho family of GTPases.^[5] It is encoded by the gene RND3.^[6]

RND3
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1M7B, 2V55, 4BG6
Identifiers
Aliases	RND3, ARHE, Rho8, RhoE, memB, Rnd3, Rho family GTPase 3
External IDs	OMIM: 602924; MGI: 1921444; HomoloGene: 21074; GeneCards: RND3; OMA:RND3 - orthologs
Gene location (Human) Chr. Chromosome 2 (human)[1] Band 2q23.3 Start 150,468,195 bp[1] End 150,539,011 bp[1]
Gene location (Mouse) Chr. Chromosome 2 (mouse)[2] Band 2|2 C1.1 Start 51,020,450 bp[2] End 51,039,123 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in amniotic fluid stromal cell of endometrium oral cavity mucosa of pharynx urethra mucosa of urinary bladder cervix epithelium ganglionic eminence human penis lactiferous duct Top expressed in genital tubercle medial ganglionic eminence tunica media of zone of aorta molar calvaria mandibular prominence cornea atrioventricular valve maxillary prominence dermis More reference expression data BioGPS More reference expression data
Gene ontology Molecular function nucleotide binding GTP binding protein binding GTPase activity protein kinase binding Cellular component Golgi membrane Golgi apparatus extracellular exosome membrane focal adhesion intracellular anatomical structure cytoplasm plasma membrane cell cortex cell division site intracellular membrane-bounded organelle Biological process small GTPase mediated signal transduction cell adhesion actin cytoskeleton organization actin filament organization Rho protein signal transduction regulation of cell shape regulation of cell migration establishment or maintenance of actin cytoskeleton polarity regulation of actin cytoskeleton organization actin filament bundle assembly Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 390 74194 Ensembl ENSG00000115963 ENSMUSG00000017144 UniProt P61587 P61588 RefSeq (mRNA) NM_005168 NM_001254738 NM_028810 RefSeq (protein) NP_001241667 NP_005159 NP_083086 Location (UCSC) Chr 2: 150.47 – 150.54 Mb Chr 2: 51.02 – 51.04 Mb PubMed search [3] [4]
Wikidata
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Like other members of the Rho family of Ras-related GTPases it regulates the organization of the actin cytoskeleton in response to extracellular growth factors.

Regulation

Most Rho family members cycle between an inactive GDP-bound form and an active GTP-bound form. However, members of the Rnd subgroup of the Rho family are exceptions to this, binding detectably only to GTP, while having low GTPase activity, if any.^[7] Instead, Rnd family proteins are regulated through other mechanisms that control their production, degradation, phosphorylation, and localization.^[8]

Interactions

In its GTP-bound form, RhoA exposes regions that allow it to interact with downstream targets. Rnd3 contains a region which is similar to the one RhoA exposes for interaction with ROCK1, allowing Rnd3 to compete with RhoA for interaction with ROCK1. By binding to ROCK1, Rnd3 inhibits it from phosphorylating downstream targets necessary for stress fiber formation. Rnd3 is also directly involved in controlling RhoA activity through suppression of PLEKHG5^[9] and activation of ARHGAP5.^[10] Interaction with UBXD5 has also been shown.^[11]