Rho-associated protein kinase

Last updated
ROCK
3d9v bio r 500.jpg
Crystal structure of human ROCK I
Identifiers
SymbolRho-associated protein kinase
Alt. symbolsRho-associated, coiled-coil-containing protein kinase
NCBI gene 579202
Other data
EC number 2.7.11.1

Rho-associated protein kinase (ROCK) is a kinase belonging to the AGC (PKA/ PKG/PKC) family of serine-threonine specific protein kinases. It is involved mainly in regulating the shape and movement of cells by acting on the cytoskeleton.

Contents

ROCKs (ROCK1 and ROCK2) occur in mammals (human, rat, mouse, cow), zebrafish, Xenopus , invertebrates ( C. elegans , mosquito, Drosophila ) and chicken. Human ROCK1 has a molecular mass of 158  kDa and is a major downstream effector of the small GTPase RhoA. Mammalian ROCK consists of a kinase domain, a coiled-coil region and a Pleckstrin homology (PH) domain, which reduces the kinase activity of ROCKs by an autoinhibitory intramolecular fold if RhoA-GTP is not present. [1] [2]

Rat ROCKs were discovered as the first effectors of Rho and they induce the formation of stress fibers and focal adhesions by phosphorylating MLC (myosin light chain). [3] Due to this phosphorylation, the actin binding of myosin II and, thus, the contractility increases. Two mouse ROCK isoforms ROCK1 and ROCK2 have been identified. ROCK1 is mainly expressed in the lung, liver, spleen, kidney and testis. However, ROCK2 is distributed mostly in the brain and heart. [1] [2] [4]

Protein kinase C and Rho-associated protein kinase are involved in regulating calcium ion intake; these calcium ions, in turn stimulate a myosin light chain kinase, forcing a contraction. [5] Rho-associated protein kinase are serine or threonine kinases that determine the calcium sensitivity in smooth muscle cells.

Function

Role and regulation of ROCK ROCK protein function.svg
Role and regulation of ROCK

ROCK plays a role in a wide range of different cellular phenomena, as ROCK is a downstream effector protein of the small GTPase Rho, which is one of the major regulators of the cytoskeleton.

1. ROCK is a key regulator of actin organization and thus a regulator of cell migration as follows:

Different substrates can be phosphorylated by ROCKs, including LIM kinase, myosin light chain (MLC) and MLC phosphatase. These substrates, once phosphorylated, regulate actin filament organization and contractility as follows: [2]

ROCK inhibits the depolymerization of actin filaments indirectly: ROCK phosphorylates and activates LIM kinase, which in turn phosphorylates ADF/cofilin, thereby inactivating its actin-depolymerization activity. This results in the stabilization of actin filaments and an increase in their numbers. Thus, over time actin monomers that are needed to continue actin polymerization for migration become limited. The increased stable actin filaments and the loss of actin monomers contribute to a reduction of cell migration. [2] [6]

ROCK also regulates cell migration by promoting cellular contraction and thus cell-substratum contacts. ROCK increases the activity of the motor protein myosin II by two different mechanisms:

  • Firstly, phosphorylation of the myosin light chain (MLC) increases the myosin II ATPase activity. Thus several bundled and active myosins, which are asynchronously active on several actin filaments, move actin filaments against each other, resulting in the net shortenting of actin fibres.
  • Secondly, ROCK inactivates MLC phosphatase, leading to increased levels of phosphorylated MLC.

Thus in both cases, ROCK activation by Rho induces the formation of actin stress fibers, actin filament bundles of opposing polarity, containing myosin II, tropomyosin, caldesmon and MLC-kinase, and consequently of focal contacts, which are immature integrin-based adhesion points with the extracellular substrate. [2] [7]

2. Other functions and targets

3. Other ROCK targets

Homologues

Rho-associated, coiled-coil-containing protein kinase 1
Identifiers
Symbol ROCK1
NCBI gene 6093
HGNC 10251
OMIM 601702
RefSeq NM_005406
UniProt Q13464
Search for
Structures Swiss-model
Domains InterPro
Rho-associated, coiled-coil-containing protein kinase 2
Identifiers
SymbolROCK2
NCBI gene 9475
HGNC 10252
OMIM 604002
RefSeq NM_004850
UniProt O75116
Search for
Structures Swiss-model
Domains InterPro

The two mouse ROCK isoforms, ROCK1 and ROCK2, have high homology. They have 65% amino acid sequences in common and 92% homology within their kinase domains. [1] [4]

ROCKs are homologous to other metazoan kinases such as myotonic dystrophy kinase (DMPK), DMPK-related cell division control protein 42 (Cdc42)-binding kinases (MRCK) and citron kinase. All of these kinases are composed of a N-terminal kinase domain, a coiled-coil structure and other functional motifs at the C-terminus [2]

Regulation

ROCK is a downstream effector molecule of the Rho GTPase Rho that increases ROCK kinase activity when bound to it.

Autoinhibition

ROCK activity is regulated by the disruption of an intramolecular autoinhibition. In general, the structure of ROCK proteins consists of an N-terminal kinase domain, a coiled-coiled region and a PH domain containing a cystein-rich domain (CRD) at the C-terminal. A Rho-binding domain (RBD) is located in close proximity just in front of the PH domain.

The kinase activity is inhibited by the intramolecular binding between the C-terminal cluster of RBD domain and the PH domain to the N-terminal kinase domain of ROCK. Thus, the kinase activity is off when ROCK is intramolecularly folded. The kinase activity is switched on when Rho-GTP binds to the Rho-binding domain of ROCK, disrupting the autoinhibitory interaction within ROCK, which liberates the kinase domain because ROCK is then no longer intramolecularly folded. [2]

Other regulators

It has also been shown that Rho is not the only activator of ROCK. ROCK can also be regulated by lipids, in particular arachidonic acid, and protein oligomerization, which induces N-terminal transphosphorylation. [2]

Inhibitors

Disease

Research over the past two decades has shown that ROCK signaling plays an important role in many diseases including cardiovascular disease, [15] [16] neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis, [17] and cancer. [18] For example, ROCK has been hypothesized to play an important role in the pleiotropic effects of statins. ROCK1/2 along with MRCKα/β kinases have been implicated in the plasticity of cancer cell migration, the phenomenon which bestows survival advantage to the cancer cells during drug treatments (drug resistance). [19]

Researchers are developing ROCK inhibitors such as RKI-1447 for treating various diseases including cancer. [20] [21] For example, such drugs have potential to prevent cancer from spreading by blocking cell migration, stopping cancer cells from spreading into neighboring tissue. [1]

See also

Related Research Articles

<span class="mw-page-title-main">Cytokinesis</span> Part of the cell division process

Cytokinesis is the part of the cell division process during which the cytoplasm of a single eukaryotic cell divides into two daughter cells. Cytoplasmic division begins during or after the late stages of nuclear division in mitosis and meiosis. During cytokinesis the spindle apparatus partitions and transports duplicated chromatids into the cytoplasm of the separating daughter cells. It thereby ensures that chromosome number and complement are maintained from one generation to the next and that, except in special cases, the daughter cells will be functional copies of the parent cell. After the completion of the telophase and cytokinesis, each daughter cell enters the interphase of the cell cycle.

<span class="mw-page-title-main">Smooth muscle</span> Involuntary non-striated muscle

Smooth muscle is an involuntary non-striated muscle, so-called because it has no sarcomeres and therefore no striations. It is divided into two subgroups, single-unit and multiunit smooth muscle. Within single-unit muscle, the whole bundle or sheet of smooth muscle cells contracts as a syncytium.

<span class="mw-page-title-main">Myosin</span> Superfamily of motor proteins

Myosins are a superfamily of motor proteins best known for their roles in muscle contraction and in a wide range of other motility processes in eukaryotes. They are ATP-dependent and responsible for actin-based motility.

<span class="mw-page-title-main">Myosin light-chain kinase</span> Class of kinase enzymes

Myosin light-chain kinase also known as MYLK or MLCK is a serine/threonine-specific protein kinase that phosphorylates a specific myosin light chain, namely, the regulatory light chain of myosin II.

<span class="mw-page-title-main">Cortactin</span> Protein found in humans

Cortactin is a monomeric protein located in the cytoplasm of cells that can be activated by external stimuli to promote polymerization and rearrangement of the actin cytoskeleton, especially the actin cortex around the cellular periphery. It is present in all cell types. When activated, it will recruit Arp2/3 complex proteins to existing actin microfilaments, facilitating and stabilizing nucleation sites for actin branching. Cortactin is important in promoting lamellipodia formation, invadopodia formation, cell migration, and endocytosis.

<span class="mw-page-title-main">Aurora kinase B</span> Protein

Aurora kinase B is a protein that functions in the attachment of the mitotic spindle to the centromere.

<span class="mw-page-title-main">Transforming protein RhoA</span> Protein and coding gene in humans

Transforming protein RhoA, also known as Ras homolog family member A (RhoA), is a small GTPase protein in the Rho family of GTPases that in humans is encoded by the RHOA gene. While the effects of RhoA activity are not all well known, it is primarily associated with cytoskeleton regulation, mostly actin stress fibers formation and actomyosin contractility. It acts upon several effectors. Among them, ROCK1 and DIAPH1 are the best described. RhoA, and the other Rho GTPases, are part of a larger family of related proteins known as the Ras superfamily, a family of proteins involved in the regulation and timing of cell division. RhoA is one of the oldest Rho GTPases, with homologues present in the genomes since 1.5 billion years. As a consequence, RhoA is somehow involved in many cellular processes which emerged throughout evolution. RhoA specifically is regarded as a prominent regulatory factor in other functions such as the regulation of cytoskeletal dynamics, transcription, cell cycle progression and cell transformation.

<span class="mw-page-title-main">ROCK1</span> Protein

ROCK1 is a protein serine/threonine kinase also known as rho-associated, coiled-coil-containing protein kinase 1. Other common names are ROKβ and P160ROCK. ROCK1 is a major downstream effector of the small GTPase RhoA and is a regulator of the actomyosin cytoskeleton which promotes contractile force generation. ROCK1 plays a role in cancer and in particular cell motility, metastasis, and angiogenesis.

<span class="mw-page-title-main">Myosin-light-chain phosphatase</span>

Myosin light-chain phosphatase, also called myosin phosphatase (EC 3.1.3.53; systematic name [myosin-light-chain]-phosphate phosphohydrolase), is an enzyme (specifically a serine/threonine-specific protein phosphatase) that dephosphorylates the regulatory light chain of myosin II:

<span class="mw-page-title-main">PPP1R12A</span> Protein-coding gene in the species Homo sapiens

Protein phosphatase 1 regulatory subunit 12A is an enzyme that in humans is encoded by the PPP1R12A gene.

<span class="mw-page-title-main">MYH10</span> Protein-coding gene in the species Homo sapiens

Myosin-10 also known as myosin heavy chain 10 or non-muscle myosin IIB (NM-IIB) is a protein that in humans is encoded by the MYH10 gene. Non-muscle myosins are expressed in a wide variety of tissues, but NM-IIB is the only non-muscle myosin II isoform expressed in cardiac muscle, where it localizes to adherens junctions within intercalated discs. NM-IIB is essential for normal development of cardiac muscle and for integrity of intercalated discs. Mutations in MYH10 have been identified in patients with left atrial enlargement.

<span class="mw-page-title-main">Citron kinase</span> Enzyme found in humans

Citron Rho-interacting kinase is an enzyme that in humans is encoded by the CIT gene.

<span class="mw-page-title-main">ANLN</span> Mammalian protein found in Homo sapiens

Anillin is a conserved protein implicated in cytoskeletal dynamics during cellularization and cytokinesis. The ANLN gene in humans and the scraps gene in Drosophila encode Anillin. In 1989, anillin was first isolated in embryos of Drosophila melanogaster. It was identified as an F-actin binding protein. Six years later, the anillin gene was cloned from cDNA originating from a Drosophila ovary. Staining with anti-anillin antibody showed the anillin localizes to the nucleus during interphase and to the contractile ring during cytokinesis. These observations agree with further research that found anillin in high concentrations near the cleavage furrow coinciding with RhoA, a key regulator of contractile ring formation.

<span class="mw-page-title-main">M-RIP</span> Protein-coding gene in the species Homo sapiens

Myosin phosphatase Rho-interacting protein is an enzyme that in humans is encoded by the MPRIP gene.

<span class="mw-page-title-main">Stress fiber</span> Contractile actin bundles found in non-muscle cells

Stress fibers are contractile actin bundles found in non-muscle cells. They are composed of actin (microfilaments) and non-muscle myosin II (NMMII), and also contain various crosslinking proteins, such as α-actinin, to form a highly regulated actomyosin structure within non-muscle cells. Stress fibers have been shown to play an important role in cellular contractility, providing force for a number of functions such as cell adhesion, migration and morphogenesis.

<span class="mw-page-title-main">MYLK</span> Gene of the immunoglobulin superfamily

Myosin light chain kinase, smooth muscle also known as kinase-related protein (KRP) or telokin is an enzyme that in humans is encoded by the MYLK gene.

<span class="mw-page-title-main">FERM domain</span>

In molecular biology, the FERM domain is a widespread protein module involved in localising proteins to the plasma membrane. FERM domains are found in a number of cytoskeletal-associated proteins that associate with various proteins at the interface between the plasma membrane and the cytoskeleton. The FERM domain is located at the N terminus in the majority of proteins in which it is found.

<span class="mw-page-title-main">Calponin 1</span> Protein-coding gene in the species Homo sapiens

Calponin 1 is a basic smooth muscle protein that in humans is encoded by the CNN1 gene.

<span class="mw-page-title-main">ROCK2</span> Protein-coding gene in the species Homo sapiens

Rho associated coiled-coil containing protein kinase 2 is a protein that in humans is encoded by the ROCK2 gene. Fasudil is an inhibitor of ROCK protein.

<span class="mw-page-title-main">Actomyosin ring</span> Cellular formation during cytokinesis

In molecular biology, an actomyosin ring or contractile ring, is a prominent structure during cytokinesis. It forms perpendicular to the axis of the spindle apparatus towards the end of telophase, in which sister chromatids are identically separated at the opposite sides of the spindle forming nuclei. The actomyosin ring follows an orderly sequence of events: identification of the active division site, formation of the ring, constriction of the ring, and disassembly of the ring. It is composed of actin and myosin II bundles, thus the term actomyosin. The actomyosin ring operates in contractile motion, although the mechanism on how or what triggers the constriction is still an evolving topic. Other cytoskeletal proteins are also involved in maintaining the stability of the ring and driving its constriction. Apart from cytokinesis, in which the ring constricts as the cells divide, actomyosin ring constriction has also been found to activate during wound closure. During this process, actin filaments are degraded, preserving the thickness of the ring. After cytokinesis is complete, one of the two daughter cells inherits a remnant known as the midbody ring.

References

  1. 1 2 3 4 Hahmann C, Schroeter T (January 2010). "Rho-kinase inhibitors as therapeutics: from pan inhibition to isoform selectivity". Cellular and Molecular Life Sciences. 67 (2): 171–7. doi:10.1007/s00018-009-0189-x. PMID   19907920. S2CID   6445354.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 Riento K, Ridley AJ (June 2003). "Rocks: multifunctional kinases in cell behaviour". Nature Reviews. Molecular Cell Biology. 4 (6): 446–56. doi:10.1038/nrm1128. PMID   12778124. S2CID   40665081.
  3. Leung T, Chen XQ, Manser E, Lim L (October 1996). "The p160 RhoA-binding kinase ROK alpha is a member of a kinase family and is involved in the reorganization of the cytoskeleton". Molecular and Cellular Biology. 16 (10): 5313–27. doi:10.1128/mcb.16.10.5313. PMC   231530 . PMID   8816443.
  4. 1 2 Nakagawa O, Fujisawa K, Ishizaki T, Saito Y, Nakao K, Narumiya S (August 1996). "ROCK-I and ROCK-II, two isoforms of Rho-associated coiled-coil forming protein serine/threonine kinase in mice". FEBS Letters. 392 (2): 189–93. doi: 10.1016/0014-5793(96)00811-3 . PMID   8772201. S2CID   6684411.
  5. Anjum I (June 2018). "Calcium sensitization mechanisms in detrusor smooth muscles". Journal of Basic and Clinical Physiology and Pharmacology. 29 (3): 227–235. doi:10.1515/jbcpp-2017-0071. PMID   29306925. S2CID   20486807.
  6. Maekawa M, Ishizaki T, Boku S, Watanabe N, Fujita A, Iwamatsu A, Obinata T, Ohashi K, Mizuno K, Narumiya S (August 1999). "Signaling from Rho to the actin cytoskeleton through protein kinases ROCK and LIM-kinase". Science. 285 (5429): 895–8. doi:10.1126/science.285.5429.895. PMID   10436159.
  7. Wang Y, Zheng XR, Riddick N, Bryden M, Baur W, Zhang X, Surks HK (February 2009). "ROCK isoform regulation of myosin phosphatase and contractility in vascular smooth muscle cells". Circulation Research. 104 (4): 531–40. doi:10.1161/CIRCRESAHA.108.188524. PMC   2649695 . PMID   19131646.
  8. Li Z, Dong X, Dong X, Wang Z, Liu W, Deng N, Ding Y, Tang L, Hla T, Zeng R, Li L, Wu D (April 2005). "Regulation of PTEN by Rho small GTPases". Nature Cell Biology. 7 (4): 399–404. doi:10.1038/ncb1236. PMID   15793569. S2CID   19316266.
  9. "Entrez Gene: PTEN phosphatase and tensin homolog (mutated in multiple advanced cancers 1)".
  10. Gao SY, Li CY, Chen J, Pan L, Saito S, Terashita T, Saito K, Miyawaki K, Shigemoto K, Mominoki K, Matsuda S, Kobayashi N (2004). "Rho-ROCK signal pathway regulates microtubule-based process formation of cultured podocytes--inhibition of ROCK promoted process elongation". Nephron Experimental Nephrology. 97 (2): e49–61. doi:10.1159/000078406. PMID   15218323. S2CID   45342422.
  11. Drechsel DN, Hyman AA, Hall A, Glotzer M (January 1997). "A requirement for Rho and Cdc42 during cytokinesis in Xenopus embryos". Current Biology. 7 (1): 12–23. doi: 10.1016/S0960-9822(06)00023-6 . PMID   8999996. S2CID   16144917.
  12. Kosako H, Yoshida T, Matsumura F, Ishizaki T, Narumiya S, Inagaki M (December 2000). "Rho-kinase/ROCK is involved in cytokinesis through the phosphorylation of myosin light chain and not ezrin/radixin/moesin proteins at the cleavage furrow". Oncogene. 19 (52): 6059–64. doi: 10.1038/sj.onc.1203987 . PMID   11146558. S2CID   39115039.
  13. Yasui Y, Amano M, Nagata K, Inagaki N, Nakamura H, Saya H, Kaibuchi K, Inagaki M (November 1998). "Roles of Rho-associated kinase in cytokinesis; mutations in Rho-associated kinase phosphorylation sites impair cytokinetic segregation of glial filaments". The Journal of Cell Biology. 143 (5): 1249–58. doi:10.1083/jcb.143.5.1249. PMC   2133074 . PMID   9832553.
  14. Piekny AJ, Mains PE (June 2002). "Rho-binding kinase (LET-502) and myosin phosphatase (MEL-11) regulate cytokinesis in the early Caenorhabditis elegans embryo". Journal of Cell Science. 115 (Pt 11): 2271–82. doi: 10.1242/jcs.115.11.2271 . PMID   12006612.
  15. Sladojevic N, Yu B, Liao JK (December 2017). "ROCK as a therapeutic target for ischemic stroke". Expert Review of Neurotherapeutics. 17 (12): 1167–1177. doi:10.1080/14737175.2017.1395700. PMC   6221831 . PMID   29057688.
  16. Yu B, Sladojevic N, Blair JE, Liao JK (January 2020). "Targeting Rho-associated coiled-coil forming protein kinase (ROCK) in cardiovascular fibrosis and stiffening". Expert Opinion on Therapeutic Targets. 24 (1): 47–62. doi:10.1080/14728222.2020.1712593. ISSN   1744-7631. PMC   7662835 . PMID   31906742. S2CID   210043399.
  17. Chong CM, Ai N, Lee SM (2017). "ROCK in CNS: Different Roles of Isoforms and Therapeutic Target for Neurodegenerative Disorders". Current Drug Targets. 18 (4): 455–462. doi:10.2174/1389450117666160401123825. ISSN   1873-5592. PMID   27033194.
  18. Wei L, Surma M, Shi S, Lambert-Cheatham N, Shi J (August 2016). "Novel Insights into the Roles of Rho Kinase in Cancer". Archivum Immunologiae et Therapiae Experimentalis. 64 (4): 259–78. doi:10.1007/s00005-015-0382-6. PMC   4930737 . PMID   26725045.
  19. Kale, Vijay Pralhad; Hengst, Jeremy A.; Desai, Dhimant H.; Amin, Shantu G.; Yun, Jong K. (2015-06-01). "The regulatory roles of ROCK and MRCK kinases in the plasticity of cancer cell migration". Cancer Letters. 361 (2): 185–196. doi:10.1016/j.canlet.2015.03.017. ISSN   0304-3835. PMID   25796438.
  20. Kale, Vijay Pralhad; Hengst, Jeremy A.; Desai, Dhimant H.; Dick, Taryn E.; Choe, Katherine N.; Colledge, Ashley L.; Takahashi, Yoshinori; Sung, Shen-Shu; Amin, Shantu G.; Yun, Jong K. (2014-11-28). "A novel selective multikinase inhibitor of ROCK and MRCK effectively blocks cancer cell migration and invasion". Cancer Letters. 354 (2): 299–310. doi:10.1016/j.canlet.2014.08.032. ISSN   0304-3835. PMC   4182185 . PMID   25172415.
  21. Feng Y, LoGrasso PV, Defert O, Li R (March 2016). "Rho Kinase (ROCK) Inhibitors and Their Therapeutic Potential". Journal of Medicinal Chemistry. 59 (6): 2269–2300. doi:10.1021/acs.jmedchem.5b00683. ISSN   1520-4804. PMID   26486225.