Guanine nucleotide-binding protein subunit alpha-13
Function
Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems (PubMed:15240885, PubMed:16705036, PubMed:16787920, PubMed:27084452). Activates effector molecule RhoA by binding and activating RhoGEFs (ARHGEF1/p115RhoGEF, ARHGEF11/PDZ-RhoGEF and ARHGEF12/LARG) (PubMed:12515866, PubMed:15240885). GNA13-dependent Rho signaling subsequently regulates transcription factor AP-1 (activating protein-1) (By similarity). Promotes tumor cell invasion and metastasis by activating RhoA/ROCK signaling pathway (PubMed:16705036, PubMed:16787920, PubMed:27084452). Inhibits CDH1-mediated cell adhesion in process independent from Rho activation (PubMed:11976333).
Post-translational modifications
Palmitoylation is critical for proper membrane localization and signaling.
Phosphorylation on Thr-203 by PKA destabilizes the heterotrimer of alpha, beta and gamma, and inhibits Rho activation.
Sequence Similarities
Belongs to the G-alpha family. G(12) subfamily.
Tissue Specificity
Expressed in testis, including in Leydig cells and in the seminiferous epithelium, in differentiating cells from the spermatogonia to mature spermatozoa stages and round spermatids (at protein level). Expressed in 99.2% of spermatozoa from healthy individuals, but only in 28.6% of macrocephalic spermatozoa from infertile patients (at protein level).
Cellular localization
- Cell membrane
- Lipid-anchor
- Melanosome
- Cytoplasm
- Nucleus
- Identified by mass spectrometry in melanosome fractions from stage I to stage IV (PubMed:17081065). Detected in the cytoplasm of Leydig cells and in the seminiferous epithelium, including differentiating cells from the spermatogonia to mature spermatozoa stages (PubMed:18703424). In round spermatids, also present in the nuclei (PubMed:18703424).
Alternative names
Guanine nucleotide-binding protein subunit alpha-13, G alpha-13, G-protein subunit alpha-13, GNA13