ROP GTPase

ROP Protein Structure
Dark Blue possible binding sites at amino acid locations 13-20, 60-64, and 118-121
Yellow beta sheets
Cyan alpha helices
Red potential phosphorylation site for protein activity regulation; serine residue at amino acid 74
PBD AF-P92978-F1
UniProt [1]

Rho-related GTPases from plants, otherwise known as ROPs, are involved in cell polarity through the regulation of cytoskeleton components like actin and microtubules.[1][2] Unlike mammalian cells, plant cells do not contain heterotrimeric G proteins like Cdc42, Rac, and Rho that are known to regulate cellular polarity.[2]

Structure and Function

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ROP proteins are a type of monomeric G proteins found in plants belonging to the Rho family.[1] ROP binding to GTP or GDP determines its activity due to conformational changes within its structure.[1] Within the G-domain of the structure are the G-box motifs G1-5. These motifs are formed during protein folding and are composed of conserved sequences that are responsible for nucleotide and magnesium binding as well as hydrolysis of GTP.[1] Motifs G2 (switch I loop) and G3 (switch II loop) possess distinct conformations depending on GTP binding state.[1] In addition, the G-domain contains a unique and conserved helical domain commonly found in Rho family proteins called αi.[1]

Specific locations within the 3D ROP protein structure, including the amino acids 13-20, 60-64, and 118-121, act as binding sites during protein activity.[3] The serine residue at amino acid 74 has been shown to be a potential protein activity regulation site through phosphorylation.[4]

References

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  1. ^ a b c d e f Ou, Hongxin; Yi, Peishan (13 July 2022). "ROP GTPase-dependent polarity establishment during tip growth in plants". New Phytologist. 236 (1): 49–57. doi:10.1111/nph.18373. PMID 35832004. S2CID 250529868 – via New Phytologist Foundation.
  2. ^ a b Fu, Ying; Yang, Zhenbiao (1 December 2001). "Rop GTPase: a master switch of cell polarity development in plants". Trends in Plant Science. 6 (12): 545–547. doi:10.1016/S1360-1385(01)02130-6. PMID 11738369 – via Cell Press.
  3. ^ "UniProt". www.uniprot.org. Retrieved 2023-05-04.
  4. ^ Ménesi, Dalma; Klement, Éva; Ferenc, Györgyi; Fehér, Attila (2021). "The Arabidopsis Rho of Plants GTPase ROP1 Is a Potential Calcium-Dependent Protein Kinase (CDPK) Substrate". Plants. 10 (10) (published 29 September 2021): 2053. doi:10.3390/plants10102053. ISSN 2223-7747. PMC 8539224. PMID 34685862.