Key References

  • Lee C, Bhatt S, Shukla A, Desnoyer RW, Yadav SP, Kim M, Jang SH, Karnik SS. Site-specific cleavage of G protein-coupled receptor-engaged beta-arrestin. Influence of the AT1 receptor conformation on scissile site selection. J Biol Chem 283:21612–21620, 2008. PMID: 18505723
  • Ramchandran R, Takezako T, Saad Y, Stull L, Fink B, Yamada H, Dikalov S, Harrison DG, Moravec C, Karnik SS. Angiotensinergic stimulation of vascular endothelium in mice causes hypotension, bradycardia and attenuated angiotensin response. Proc Natl Acad Sci USA103:19087–19097, 2006. PMID: 17148616
  • Baleanu-Gogonea C, Karnik S. Model of the whole rat AT1 receptor and the ligand binding site. J Mol Model 12:325–337, 2006. Epub January 11, 2006. PMID: 16404618
  • Perez D, Karnik, SS. Multiple signaling states of G-protein-coupled receptors. Pharm Rev 57:1–15, 2005. PMID: 15914464
  • Pucadyil TJ, Kalipatnapu S, Harikumar KG, Rangaraj N, Karnik SS, Chattopadhyay A. G-protein-dependent cell surface dynamics of the human serotonin 1A receptor tagged with yellow fluorescent protein. Biochemistry 43:15852–15862, 2004. PMID: 15595840
  • Takazako T, Gogonea C, Saad Y, Noda K, Karnik SS. “Network leaning” as a mechanism of insurmountable antagonism of AT1 receptor by candesartan. J Biol Chem 279:15248–15257, 2004. PMID: 14754891
  • Karnik SS, Gogonea C, Saad Y, Patil S, Takezako T. Activation of G-protein-coupled receptors: a common molecular mechanism. Trends Endocrinol Metab 14:431–437, 2003. PMID: 14580763
  • Wei H, Ahn S, Shenoy SK, Karnik SS, Hunyady L, Luttrell LM, Lefkowitz RJ. Independent beta-arrestin 2 and G protein-mediated pathways for angiotensin II activation of extracellular signal-regulated kinases 1 and 2. Proc Natl Acad Sci USA 100:10782–10787, 2003. PMID: 12949261
  • Miura SI, Zhang J, Boros J, Karnik SS. TM2-TM7 interaction in coupling movement of transmembrane helices to activation of the angiotensin II type-1 receptor. J Biol Chem 278:3720–3725. 2003. PMID: 12446719
  • Miura SI, Karnik SS. Constitutive activation of angiotensin II type-1 receptor alters the orientation of transmembrane helix-2. J Biol Chem 277:24299–24305, 2002. PMID: 11983705
  • Holloway AC, Qian H, Pipolo L, Ziogas J, Miura S, Southwell BR, Lew MJ, Thomas WG, Karnik SS. Side-chain substitution within angiotensin II reveal different requirements for signaling, internalization and phosphorylation of type 1A angiotensin receptors. Mol Pharmcol 61:768–777, 2002. PMID: 11901215
  • Karnik SS. Analysis of structure-function from expression of G protein coupled receptor fragments. Methods Enzymol 343:248–259, 2002. PMID: 11665571
  • Feng Y-H, Saad Y, Karnik SS. Reversible inactivation of AT2 angiotensin II receptor from cysteine-disulfi bond exchange. FEBS Lett 484:133–138, 2000. PMID: 11068047
  • Miura SI, Karnik SS. Ligand-independent signals from the angiotensin II type-2 receptor induce apoptosis. EMBO J 19:4026–40356, 2000. PMID: 10921883
  • Thomas WG, Qian H, Chang C-S, Karnik SS. Agonist-induced phosphorylation of the angiotensin II (AT1A) receptor requires generation of a conformation that is distinct from the inositol phosphate-signaling state. J Biol Chem. 275:2893–2900, 2000. PMID: 10644757
  • Feng Y-H, Karnik SS. Role of transmembrane helix-IV in G-protein specificity of angiotensin II type-1. J Biol Chem 274:35546–35552, 1999. PMID: 10585429
  • Miura SI, Karnik SS. Angiotensin II type 1 and type 2 receptors bind angiotensin II through different epitope recognition. J Hypertension 17:397–404, 1999. PMID: 10100078
  • Miura SI, Feng Y-H, Husain A, Karnik SS. Role of aromaticity of agonist switch residues of angiotensin II in the activation of the AT1 receptor. J Biol Chem 274:7103–7109, 1999. PMID: 10066768
  • Feng Y-H, Miura SI, Husain A, Karnik SS. Mechanism of constitutive activation of the AT1 receptor: Influence of the size of the agonist- switch binding residue Asn111. Biochemistry 37:15791–15798, 1998. PMID: 9843384
  • Acharya S, Saad Y, Karnik SS. Transducin-alpha C-terminal peptide binds to the cytoplasmic E-F loop of activated rhodopsin. J Biol Chem 272:6519–6524, 1997. PMID: 9045677
  • Noda K, Feng Y-H, Liu X-P, Saad YM, Husain A, Karnik SS. The active state of the AT1 angiotensin receptor is generated by angiotensin II induction. Biochemistry 35:16435–16442, 1996. PMID: 8987975
  • Acharya S, Karnik SS. Modulation of GDP release from transducin by the conserved Glu134Arg135 sequence in rhodopsin. J Biol Chem 271:25406–25411, 1996. PMID: 8810308
  • Chandrasekharan UM. Sanker S, Glynias MJ, Karnik SS, Husain A. Angiotensin II forming activity in a reconstructed ancestral chymase. Science 271:502–505, 1996. PMID: 8560264
  • Murakami M, Karnik SS, Husain A. Human prochymase activation: A novel role for heparin in zymogen processing. J Biol Chem 270:2218–2223, 1995. PMID: 7836453
  • Noda K, Kinoshita A, Saad YM, Boyle T, Husain A, Graham RM, Karnik SS. Tetrazole and carboxylate groups of angiotensin receptor antagonists bind to the same subsite by different mechanisms. J Biol Chem 270:2284–2289, 1995. PMID: 7530721
  • Noda KN, Saad Y, Karnik SS. Interaction of Phe8 of angiotensin II with Lys199 and His256 of AT1 receptor in agonist activation. J Biol Chem 270:25811–25814, 1995. PMID: 7499361
  • Noda K, Saad Y, Graham RM, Karnik SS. The high-affinity state of the beta2-adrenergic receptor requires unique interaction between conserved and non-conserved extracellular loop cysteines. J Biol Chem 269:6743–6752, 1994. PMID: 8120034
  • Karnik SS, Ridge KD, Bhattacharya SS, Khorana HG. Palmitoylation of bovine opsin and its cysteine mutants in COS cells. Proc Natl Acad Sci USA 90:40–44, 1993. PMID: 8419942
  • Urata H, Karnik SS, Graham RM, Husain A. Dipeptide processing activates recombinant human prochymase. J Biol Chem 268:24318–24322, 1993. PMID: 8226981
  • Karnik SS, Doi T, Molday R, Khorana MG. Expression of the archaebacterial bacterio-opsin gene with and without signal sequences in Escherchia coli: the expressed proteins are located in the membrane but bind retinal poorly. Proc Natl Acad Sci USA 87:8955–8959, 1990. PMID: 2247471
  • Karnik SS, Sakmar T, Chen H-B, Khorana HG. Cysteine residues 110 and 187 are required for the formation of correct tertiary structure in bovine rhodopsin. Proc Natl Acad Sci USA 85:8459–8463, 1988. PMID: 3186735
  • Karnik SS, Nassal M, Doi T, Khorana HG. Structure-function studies on bacteriorhodopsin. II. Improved expression of bacterio-opsin gene in Escherichia coli. J Biol Chem 262:9255–9263, 1987. PMID: 3298253
  • Ferretti L, Karnik SS, Khorana HG, Nassal MN, Oprian DD. Total synthesis of a bovine rhodopsin gene. Proc Natl Acad Sci USA 83:599–603, 1986. PMID: 3456156