Harold Paul Erickson


James B. Duke Professor of Cell Biology

Cytoskeleton: It is now clear that the actin and microtubule cytoskeleton originated in bacteria. Our major research is on FtsZ, the bacterial tubulin homolog, which assembles into a contractile ring that divides the bacterium. We have studied FtsZ assembly in vitro, and found that it assembles into thin protofilaments (pfs). Dozens of these pfs are further clustered to form the contractile Z-ring in vivo. Some important discoveries in the last ten years include:

•    Reconstitution of Z rings in vitro. We provided FtsZ with a membrane tether, and found that when incorporated inside liposomes, FtsZ-mts can assemble Z rings without any other proteins.

•    These reconstituted Z rings generate a constriction force on the membranes, again without any other proteins (no motor molecules).

•    The constriction force is generated by a curved conformation of FtsZ pfs generating a bending force on the membrane.

Important questions for the future are:

  • How are FtsZ pfs arranged in the Z ring? We favor the ribbon model, where pfs are parallel and laterally associated into a ribbon. Many others in the field favor a scattered model, where pfs are more widely separated. We are exploring new electron microscopy (EM) methods to resolve the structure. We have also developed new tools to facilitate superresolution light microscopy (PALM).
  • How does FtsZ treadmilling work? Our lab provided the first evidence that FtsZ treadmills, adding subunits at one end and losing them at the other (Redick J Bact 2005). This has now been confirmed in vitro and in vivo. We are developing theoretical models and experimental (EM) methods to determine the detailed mechanism of treadmilling.
  • What is the structure of the septum in dividing bacteria? There is wide agreement that Gram-positive bacteria divide by ingression of a plate-like septum. Conventional EM suggests that Gram-negative bacteria have a shallower V-shaped constriction. We are revisiting this using novel fixatives and high-pressure freezing for thin section EM.

Irisin. We believe the irisin story is bunk. Irisin was proposed in 2012 as a novel myokine, secreted by muscle cells in response to exercise, it induces the transformation of white fat to brown fat. This inspired hopes of an exercise pill that might correct obesity and other metabolic disorders. We have argued that the original discovery was flawed in several respects (Erickson, Adipocyte, 2013), and that the 300+ published follow-up studies are based on flawed commercial antibodies (Albrecht et al, Sci Rep 2015). We are now developing new assays to determine if irisin exists in in the blood of humans, primates and other animals. We expect it does not, especially in humans whose FNDC5 gene has a mutated start codon.

Appointments and Affiliations

  • James B. Duke Professor of Cell Biology
  • Professor of Cell Biology
  • Professor of Biomedical Engineering
  • Professor of Biochemistry
  • Member of the Duke Cancer Institute

Contact Information


  • Ph.D. Johns Hopkins University, 1968

Courses Taught

  • BIOCHEM 393: Research Independent Study
  • BIOCHEM 593: Research Independent Study
  • CELLBIO 493: Research Independent Study
  • CELLBIO 710: Papers and Grant Writing Workshop
  • CMB 710E: Cell & Molecular Biology Module V
  • MOLCAN 710: Papers and Grant Writing Workshop
  • NEUROBIO 710: Papers and Grant Writing Workshop
  • PHARM 710: Papers and Grant Writing Workshop

In the News

Representative Publications

  • Lemmon, CA; Ohashi, T; Erickson, HP, Probing the folded state of fibronectin type III domains in stretched fibrils by measuring buried cysteine accessibility., The Journal of Biological Chemistry, vol 286 no. 30 (2011), pp. 26375-26382 [10.1074/jbc.M111.240028] [abs].
  • Osawa, M; Erickson, HP, Inside-out Z rings--constriction with and without GTP hydrolysis., Molecular Microbiology, vol 81 no. 2 (2011), pp. 571-579 [10.1111/j.1365-2958.2011.07716.x] [abs].
  • Chen, Y; Erickson, HP, Conformational changes of FtsZ reported by tryptophan mutants., Biochemistry, vol 50 no. 21 (2011), pp. 4675-4684 [10.1021/bi200106d] [abs].
  • Erickson, HP; Anderson, DE; Osawa, M, FtsZ in bacterial cytokinesis: cytoskeleton and force generator all in one., Microbiology and Molecular Biology Reviews : Mmbr, vol 74 no. 4 (2010), pp. 504-528 [10.1128/MMBR.00021-10] [abs].
  • Erickson, HP; Osawa, M, Cell division without FtsZ--a variety of redundant mechanisms., Molecular Microbiology, vol 78 no. 2 (2010), pp. 267-270 [10.1111/j.1365-2958.2010.07321.x] [abs].
  • Popp, D; Iwasa, M; Erickson, HP; Narita, A; Maéda, Y; Robinson, RC, Suprastructures and dynamic properties of Mycobacterium tuberculosis FtsZ., The Journal of Biological Chemistry, vol 285 no. 15 (2010), pp. 11281-11289 [10.1074/jbc.M109.084079] [abs].
  • Kenjale, R; Meng, G; Fink, DL; Juehne, T; Ohashi, T; Erickson, HP; Waksman, G; St Geme, JW, Structural determinants of autoproteolysis of the Haemophilus influenzae Hap autotransporter., Infection and Immunity, vol 77 no. 11 (2009), pp. 4704-4713 [10.1128/IAI.00598-09] [abs].
  • Osawa, M; Anderson, DE; Erickson, HP, Curved FtsZ protofilaments generate bending forces on liposome membranes., The Embo Journal, vol 28 no. 22 (2009), pp. 3476-3484 [10.1038/emboj.2009.277] [abs].
  • Sontag, CA; Sage, H; Erickson, HP, BtubA-BtubB heterodimer is an essential intermediate in protofilament assembly., Plos One, vol 4 no. 9 (2009) [10.1371/journal.pone.0007253] [abs].
  • Chen, Y; Erickson, HP, FtsZ filament dynamics at steady state: subunit exchange with and without nucleotide hydrolysis., Biochemistry, vol 48 no. 28 (2009), pp. 6664-6673 [10.1021/bi8022653] [abs].
  • Erickson, HP, Modeling the physics of FtsZ assembly and force generation., Proceedings of the National Academy of Sciences of the United States of America, vol 106 no. 23 (2009), pp. 9238-9243 [10.1073/pnas.0902258106] [abs].
  • Ohashi, T; Augustus, AM; Erickson, HP, Transient opening of fibronectin type III (FNIII) domains: the interaction of the third FNIII domain of FN with anastellin., Biochemistry, vol 48 no. 19 (2009), pp. 4189-4197 [10.1021/bi900001g] [abs].
  • Popp, D; Iwasa, M; Narita, A; Erickson, HP; Maéda, Y, FtsZ condensates: an in vitro electron microscopy study., Biopolymers, vol 91 no. 5 (2009), pp. 340-350 [10.1002/bip.21136] [abs].
  • Ohashi, T; Erickson, HP, Revisiting the mystery of fibronectin multimers: the fibronectin matrix is composed of fibronectin dimers cross-linked by non-covalent bonds., Matrix Biology : Journal of the International Society for Matrix Biology, vol 28 no. 3 (2009), pp. 170-175 [10.1016/j.matbio.2009.03.002] [abs].
  • Erickson, HP, Size and shape of protein molecules at the nanometer level determined by sedimentation, gel filtration, and electron microscopy., Biological Procedures Online, vol 11 (2009), pp. 32-51 [10.1007/s12575-009-9008-x] [abs].
  • Osawa, M; Erickson, HP, Chapter 1 - Tubular liposomes with variable permeability for reconstitution of FtsZ rings., Methods in Enzymology, vol 464 (2009), pp. 3-17 [10.1016/S0076-6879(09)64001-5] [abs].
  • Xu, J; Bae, E; Zhang, Q; Annis, DS; Erickson, HP; Mosher, DF, Display of cell surface sites for fibronectin assembly is modulated by cell adherence to (1)F3 and C-terminal modules of fibronectin., Plos One, vol 4 no. 1 (2009) [10.1371/journal.pone.0004113] [abs].
  • White, GE; Erickson, HP, The coiled coils of cohesin are conserved in animals, but not in yeast., Plos One, vol 4 no. 3 (2009) [10.1371/journal.pone.0004674] [abs].
  • Takahashi, S; Leiss, M; Moser, M; Ohashi, T; Kitao, T; Heckmann, D; Pfeifer, A; Kessler, H; Takagi, J; Erickson, HP; Fässler, R, The RGD motif in fibronectin is essential for development but dispensable for fibril assembly., The Journal of Cell Biology, vol 178 no. 1 (2007), pp. 167-178 [10.1083/jcb.200703021] [abs].
  • Erickson, HP, Evolution of the cytoskeleton., Bioessays, vol 29 no. 7 (2007), pp. 668-677 [10.1002/bies.20601] [abs].
  • Ohashi, T; Galiacy, SD; Briscoe, G; Erickson, HP, An experimental study of GFP-based FRET, with application to intrinsically unstructured proteins., Protein Science : a Publication of the Protein Society, vol 16 no. 7 (2007), pp. 1429-1438 [10.1110/ps.072845607] [abs].
  • Osawa, M; Erickson, HP, FtsZ from divergent foreign bacteria can function for cell division in Escherichia coli., Journal of Bacteriology, vol 188 no. 20 (2006), pp. 7132-7140 [10.1128/JB.00647-06] [abs].
  • White, GE; Erickson, HP, Sequence divergence of coiled coils--structural rods, myosin filament packing, and the extraordinary conservation of cohesins., Journal of Structural Biology, vol 154 no. 2 (2006), pp. 111-121 [10.1016/j.jsb.2006.01.001] [abs].
  • Osawa, M; Erickson, HP, Probing the domain structure of FtsZ by random truncation and insertion of GFP., Microbiology, vol 151 no. Pt 12 (2005), pp. 4033-4043 [10.1099/mic.0.28219-0] [abs].
  • Ohashi, T; Erickson, HP, Domain unfolding plays a role in superfibronectin formation., The Journal of Biological Chemistry, vol 280 no. 47 (2005), pp. 39143-39151 [10.1074/jbc.M509082200] [abs].
  • Chen, Y; Erickson, HP, Rapid in vitro assembly dynamics and subunit turnover of FtsZ demonstrated by fluorescence resonance energy transfer., The Journal of Biological Chemistry, vol 280 no. 23 (2005), pp. 22549-22554 [10.1074/jbc.M500895200] [abs].
  • Sontag, CA; Staley, JT; Erickson, HP, In vitro assembly and GTP hydrolysis by bacterial tubulins BtubA and BtubB., The Journal of Cell Biology, vol 169 no. 2 (2005), pp. 233-238 [10.1083/jcb.200410027] [abs].
  • Redick, SD; Stricker, J; Briscoe, G; Erickson, HP, Mutants of FtsZ targeting the protofilament interface: effects on cell division and GTPase activity., Journal of Bacteriology, vol 187 no. 8 (2005), pp. 2727-2736 [10.1128/JB.187.8.2727-2736.2005] [abs].
  • Chen, Y; Bjornson, K; Redick, SD; Erickson, HP, A rapid fluorescence assay for FtsZ assembly indicates cooperative assembly with a dimer nucleus., Biophysical Journal, vol 88 no. 1 (2005), pp. 505-514 [10.1529/biophysj.104.044149] [abs].
  • Anderson, DE; Gueiros-Filho, FJ; Erickson, HP, Assembly dynamics of FtsZ rings in Bacillus subtilis and Escherichia coli and effects of FtsZ-regulating proteins., Journal of Bacteriology, vol 186 no. 17 (2004), pp. 5775-5781 [10.1128/JB.186.17.5775-5781.2004] [abs].
  • Ohashi, T; Erickson, HP, The disulfide bonding pattern in ficolin multimers., The Journal of Biological Chemistry, vol 279 no. 8 (2004), pp. 6534-6539 [10.1074/jbc.m310555200] [abs].
  • Stricker, J; Erickson, HP, In vivo characterization of Escherichia coli ftsZ mutants: effects on Z-ring structure and function., Journal of Bacteriology, vol 185 no. 16 (2003), pp. 4796-4805 [10.1128/JB.185.16.4796-4805.2003] [abs].
  • Ohashi, T; Kiehart, DP; Erickson, HP, Dual labeling of the fibronectin matrix and actin cytoskeleton with green fluorescent protein variants., Journal of Cell Science, vol 115 no. Pt 6 (2002), pp. 1221-1229 [abs].
  • Stricker, J; Maddox, P; Salmon, ED; Erickson, HP, Rapid assembly dynamics of the Escherichia coli FtsZ-ring demonstrated by fluorescence recovery after photobleaching., Proceedings of the National Academy of Sciences of the United States of America, vol 99 no. 5 (2002), pp. 3171-3175 [10.1073/pnas.052595099] [abs].
  • Erickson, HP, Stretching fibronectin., Journal of Muscle Research and Cell Motility, vol 23 no. 5-6 (2002), pp. 575-580 [abs].
  • Erickson, HP, Gamma-tubulin nucleation: template or protofilament?, Nature Cell Biology, vol 2 no. 6 (2000), pp. E93-E96 [10.1038/35014084] [abs].
  • Redick, SD; Settles, DL; Briscoe, G; Erickson, HP, Defining fibronectin's cell adhesion synergy site by site-directed mutagenesis., The Journal of Cell Biology, vol 149 no. 2 (2000), pp. 521-527 [10.1083/jcb.149.2.521] [abs].
  • Ohashi, T; Kiehart, DP; Erickson, HP, Dynamics and elasticity of the fibronectin matrix in living cell culture visualized by fibronectin-green fluorescent protein., Proceedings of the National Academy of Sciences of the United States of America, vol 96 no. 5 (1999), pp. 2153-2158 [abs].
  • Ohashi, T; Erickson, HP, Oligomeric structure and tissue distribution of ficolins from mouse, pig and human., Archives of Biochemistry and Biophysics, vol 360 no. 2 (1998), pp. 223-232 [10.1006/abbi.1998.0957] [abs].
  • Melby, TE; Ciampaglio, CN; Briscoe, G; Erickson, HP, The symmetrical structure of structural maintenance of chromosomes (SMC) and MukB proteins: long, antiparallel coiled coils, folded at a flexible hinge., The Journal of Cell Biology, vol 142 no. 6 (1998), pp. 1595-1604 [10.1083/jcb.142.6.1595] [abs].
  • O'Brien, ET; Salmon, ED; Erickson, HP, How calcium causes microtubule depolymerization., Cell Motility and the Cytoskeleton, vol 36 no. 2 (1997), pp. 125-135 [10.1002/(sici)1097-0169(1997)36:2<125::aid-cm3>3.0.co;2-8] [abs].
  • Erickson, HP; Taylor, DW; Taylor, KA; Bramhill, D, Bacterial cell division protein FtsZ assembles into protofilament sheets and minirings, structural homologs of tubulin polymers., Proceedings of the National Academy of Sciences of the United States of America, vol 93 no. 1 (1996), pp. 519-523 [abs].
  • Leahy, DJ; Aukhil, I; Erickson, HP, 2.0 A crystal structure of a four-domain segment of human fibronectin encompassing the RGD loop and synergy region., Cell, vol 84 no. 1 (1996), pp. 155-164 [10.1016/s0092-8674(00)81002-8] [abs].
  • Erickson, HP, Reversible unfolding of fibronectin type III and immunoglobulin domains provides the structural basis for stretch and elasticity of titin and fibronectin., Proceedings of the National Academy of Sciences of the United States of America, vol 91 no. 21 (1994), pp. 10114-10118 [abs].
  • Erickson, HP, Gene knockouts of c-src, transforming growth factor beta 1, and tenascin suggest superfluous, nonfunctional expression of proteins., The Journal of Cell Biology, vol 120 no. 5 (1993), pp. 1079-1081 [abs].
  • Leahy, DJ; Hendrickson, WA; Aukhil, I; Erickson, HP, Structure of a fibronectin type III domain from tenascin phased by MAD analysis of the selenomethionyl protein., Science (New York, N.Y.), vol 258 no. 5084 (1992), pp. 987-991 [abs].
  • Northrup, SH; Erickson, HP, Kinetics of protein-protein association explained by Brownian dynamics computer simulation., Proceedings of the National Academy of Sciences of the United States of America, vol 89 no. 8 (1992), pp. 3338-3342 [10.1073/pnas.89.8.3338] [abs].
  • Erickson, HP, Co-operativity in protein-protein association. The structure and stability of the actin filament., Journal of Molecular Biology, vol 206 no. 3 (1989), pp. 465-474 [abs].
  • Walker, RA; O'Brien, ET; Pryer, NK; Soboeiro, MF; Voter, WA; Erickson, HP; Salmon, ED, Dynamic instability of individual microtubules analyzed by video light microscopy: rate constants and transition frequencies., The Journal of Cell Biology, vol 107 no. 4 (1988), pp. 1437-1448 [abs].
  • Erickson, HP; Inglesias, JL, A six-armed oligomer isolated from cell surface fibronectin preparations., Nature, vol 311 no. 5983 (1984), pp. 267-269 [10.1038/311267a0] [abs].
  • Voter, WA; Erickson, HP, The kinetics of microtubule assembly. Evidence for a two-stage nucleation mechanism., The Journal of Biological Chemistry, vol 259 no. 16 (1984), pp. 10430-10438 [abs].
  • Fowler, WE; Erickson, HP, Trinodular structure of fibrinogen. Confirmation by both shadowing and negative stain electron microscopy., Journal of Molecular Biology, vol 134 no. 2 (1979), pp. 241-249 [abs].
  • Erickson, HP, Microtubule surface lattice and subunit structure and observations on reassembly., The Journal of Cell Biology, vol 60 no. 1 (1974), pp. 153-167 [abs].