Reactome | RHO GTPases Activate Rhotekin and Rhophilins

RHO GTPases Activate Rhotekin and Rhophilins

Stable Identifier

R-HSA-5666185

Type

Pathway

Species

Homo sapiens

ReviewStatus

5/5

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RHO GTPases Activate Rhotekin and Rhophilins

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Rhotekin (RTKN) is a protein with an N-terminally located RHO GTPase binding domain, that shares a limited sequence homology with PKNs and rhophilins. RTKN binds to GTP-bound RHOA, RHOB and RHOC and can inhibit their GTPase activity (Reid et al. 1996, Fu et al. 2000), which can be corroborated by protein kinase D-mediated phosphorylation of RTKN (Pusapati et al. 2012). RTKN is implicated in the establishment of cell polarity (Sudo et al. 2006), septin organization (Ito et al. 2005, Sudo et al. 2007) and stimulation of SRF-mediated transcription (Reynaud et al. 2000). RTKN can have an anti-apoptotic effect that depends on the activation of NFKB (NF-kappaB) (Liu et al. 2004). RTKN2 (rhotekin-2) is another rhotekin exclusively expressed in lymphocytes (Collier et al. 2004). The function and the mechanism of action of RTKN2 are unknown.

Rhophillins include two family members - rhophilin-1 (RHNP1) and rhophilin-2 (RHPN2) with ~75% sequence identity. A RHO GTPase binding domain is located at the N-terminus of rhophilins, followed by a BRO1 domain (characteristic of proteins involved in protein kinase C signaling) and a C-terminal PDZ domain. RHOA:GTP binds both RHPN1 and RHPN2 and these interactions may be involved in organization of the actin cytoskeleton and/or cell motility (Watanabe et al. 1996, Fujita et al. 2000, Peck et al. 2002). RHOB:GTP recruits RHPN2 to endosomes which may be involved in the function of thyroid cells (Mircescu et al. 2002).

Literature References

PubMed ID	Title	Journal	Year
12221077	The RhoA-binding protein, rhophilin-2, regulates actin cytoskeleton organization Peck, JW, Oberst, M, Bouker, KB, Bowden, E, Burbelo, PD	J. Biol. Chem.	2002
17546647	SEPT9 sequence alternations causing hereditary neuralgic amyotrophy are associated with altered interactions with SEPT4/SEPT11 and resistance to Rho/Rhotekin-signaling Sudo, K, Ito, H, Iwamoto, I, Morishita, R, Asano, T, Nagata, K	Hum. Mutat.	2007
10940294	The PDZ protein TIP-1 interacts with the Rho effector rhotekin and is involved in Rho signaling to the serum response element Reynaud, C, Fabre, S, Jalinot, P	J. Biol. Chem.	2000
8662891	Rhotekin, a new putative target for Rho bearing homology to a serine/threonine kinase, PKN, and rhophilin in the rho-binding domain Reid, T, Furuyashiki, T, Ishizaki, T, Watanabe, G, Watanabe, N, Fujisawa, K, Morii, N, Madaule, P, Narumiya, S	J. Biol. Chem.	1996
8571126	Protein kinase N (PKN) and PKN-related protein rhophilin as targets of small GTPase Rho Watanabe, G, Saito, Y, Madaule, P, Ishizaki, T, Fujisawa, K, Morii, N, Mukai, H, Ono, Y, Kakizuka, A, Narumiya, S	Science	1996
22228765	Protein kinase D regulates RhoA activity via rhotekin phosphorylation Pusapati, GV, Eiseler, T, Rykx, A, Vandoninck, S, Derua, R, Waelkens, E, Van Lint, J, von Wichert, G, Seufferlein, T	J. Biol. Chem.	2012
15480428	Rho/Rhotekin-mediated NF-kappaB activation confers resistance to apoptosis Liu, CA, Wang, MJ, Chi, CW, Wu, CW, Chen, JY	Oncogene	2004
16979770	Identification of a cell polarity-related protein, Lin-7B, as a binding partner for a Rho effector, Rhotekin, and their possible interaction in neurons Sudo, K, Ito, H, Iwamoto, I, Morishita, R, Asano, T, Nagata, K	Neurosci. Res.	2006
12473120	Identification and characterization of a novel activated RhoB binding protein containing a PDZ domain whose expression is specifically modulated in thyroid cells by cAMP Mircescu, H, Steuve, S, Savonet, V, Degraef, C, Mellor, H, Dumont, JE, Maenhaut, C, Pirson, I	Eur. J. Biochem.	2002
10873388	Molecular cloning, expression characterization, and mapping of a novel putative inhibitor of rho GTPase activity, RTKN, to D2S145-D2S286 Fu, Q, Yu, L, Liu, Q, Zhang, J, Zhang, H, Zhao, S	Genomics	2000
15504364	Identification and characterization of a lymphocytic Rho-GTPase effector: rhotekin-2 Collier, FM, Gregorio-King, CC, Gough, TJ, Talbot, CD, Walder, K, Kirkland, MA	Biochem. Biophys. Res. Commun.	2004
16007136	Possible role of Rho/Rhotekin signaling in mammalian septin organization Ito, H, Iwamoto, I, Morishita, R, Nozawa, Y, Narumiya, S, Asano, T, Nagata, K	Oncogene	2005
10591629	Ropporin, a sperm-specific binding protein of rhophilin, that is localized in the fibrous sheath of sperm flagella Fujita, A, Nakamura, K, Kato, T, Watanabe, N, Ishizaki, T, Kimura, K, Mizoguchi, A, Narumiya, S	J. Cell. Sci.	2000