Formerly Staff Scientist at IBPM-CNR
Retired Nov.1st, 2020
CNR - National Research Council, Italy
IBPM - Institute of Biology and Molecular Pathology (Nucleic Acids
c/o Dept. Biology and Biotechnology, University «La Sapienza», Rome
- In short. My main interest centres on the relevance of
chromosome architecture to genome functions (it's what I like to
call functional morphogenomics). The development of
these subjects towards more general views has led me to focus also on
the evolution and biological relevance of supramolecular assemblies in
- Following my initial training
in molecular biology and electron microscopy of nucleic acids I have
been involved in research on the supramolecular
organisation of the eukaryotic genome. This line is
exemplified by studies on the relationship between replicative
processes and the DNA loop organization of the genome, as well as
by investigations on the role of this peculiar structural level of
chromatin in determining genome complexity through the strict
association of specific DNA regions (commonly known as MAR,
SAR) to the non-histone protein framework of the nucleus (nuclear
matrix, nucleoskeleton) and of the chromosomes (scaffold).
Our observations stress (a) the nuceoskeletal association of
replicative intermediates and activities; (b) the close relationship
between units of replication and nucleoskeleton-bound DNA loops; (c)
the topological independence of each negatively supercoiled DNA loop
domain from its neighbouring ones; (d) the possible significance of
‘origin of replication’ of MARs; (e) the immediate relevance of
loop size variations to chromosome morphology ; (f) the key role
of endogenous topoisomerase activities in shaping the looped
architecture of the genome; and (g) the dependency of the binding
specificity between MARs and the nucleoskeleton not only on the
primary structure of the DNA, but also on the genomic context
surrounding MARs in vivo.
- Banking on the experience
gained through the work on the eukaryotic genome, I got involved in
studies on the organisation of the bacterial genome. The
identification of global and local determinants of genome
architecture is central also in microorganisms. As compared to
its eukaryotic counterpart, the bacterial nucleoid offers the added
advantage of a reduced biochemical and morphological complexity. Our
investigations on global determinants indicate that histone-like
proteins, surmised of being key elements in organizing the bacterial
chromatin and well known as global regulators of bacterial gene
expression, play an ancillary role in defining and maintaining the
structural constrains which account for the topological
integrity of the DNA loop domains in the bacterial nucleoid.
As for local determinants, more recently I focused on the role of
sequence-mediated DNA curvature (intrinsic bending) in the activity of
virulence promoters in human enteropathogenic bacteria, like Shigella
and E.coli EIEC. In these microorganisms the invasivity
functions are modulated antagonistically by two histone-like proteins
(H-NS and FIS), and the activation of the primary regulator (the virF
gene) is triggered by the transit of the bacteria from the outer
environment to the intestinal, warmer, milieu of the host. Our results
show (a) that, among human enteropathogenic bacteria, the involvement
of histone-like proteins in the transcriptional modulation of
virulence gene networks is a common regulative strategy; (b) that the
activation of the primary regulator is directly related to the
changes in DNA bending its promoter undergoes with changing
temperature; and (c) that an exquisitely structural feature
of DNA, like intrinsic curvature, can act as a (thermo)sensor able to
regulate gene expression in response to changing environmental
conditions. As for the overall transcriptional significance of DNA
curvature, our observations have allowed us to show that the in vitro
activity of a bacterial promoter is maximized only within a narrow
range of promoter curvature.
- In recent years I became
gradually involved also in reseach lines related to the broader
significance of my reserach interests, i.e. to the evolution and
biological relevance of supramolecular assemblies in the cell. This is
exemplified, for instance, by studies on specific bacterial systems
(e.g. efflux pumps, polyamine regulatory networks, OMVs)
- Microscopy. Since the beginning of my research activity part of my
time has always been devoted to coordinating the activity of the
IBPM's Molecular Microscopy Unit, with a
major focus on electron microscopy and atomic force microscopy of
nucleic acids and chromatin.
- Current activity.
Following my retirement (Nov.1st, 2020) I have stopped most wet-bench
work but I have maintained my interest for the above mentioned
subjects in the form of data analysis,review and elaboration,
including also the theoretical development of specific approaches and
the implementation of software tools.
(structures, processes, techniques). 3D genome architecture,
supramolecular genome structure, chromatin-loops / morphogenomics /
cell nucleus and chromosome structure / nuclear matrix,
nucleoskeleton, nuclear lamina, chromosome scaffold / bacterial
nucleoid structure / DNA, chromatin and nucleoproteins structure and
organisation / DNA topology, topoisomerases / DNA intrinsic curvature,
bending / supramolecular assemblies of the cell / epigenetics
regulation, DNA replication, transcription, gene expression / electron
microscopy, TEM, atomic force microscopy, AFM, SFM.
- Born in Rome (Italy),
October 28th, 1953.
- Nationality: Italian
- High school: Schweizerschule,
Rome, and Liceo scientifico A.Righi, Rome.
- 1980: Laurea in
Biological Sciences at the University of Rome
project: Electron microscope analysis of DNA replication in Carassius
auratus (supervisor: Prof. M.Buongiorno-Nardelli).
- 1980-1981: Research activity at
the Institute of
Embryology, Univ. Rome. Research project: Functional significance
of the supercoiled loop organization of the eukaryotic genome
(supervisor: Prof. M.Buongiorno-Nardelli).
- 1982-1983: Research fellow
of the Istituto Pasteur-Fondazione Cenci Bolognetti
(Univ.Rome) at the Zoologisches Institut (Abt. Zell- und
Entwicklungsbiologie), Univ. Bern (Switzerland). Research project: Organisation of globin genes in
Xenopus laevis (supervisor: Prof. R. Weber).
- 1983: Research assistant at
the Zoologisches Institut (Abt. Zell-
und Entwicklungsbiologie), Univ. Bern (Switzerland).
Research project/supervisor: as above.
- Since 1984: staff scientist of
the Italian National Research Council (CNR.) at the Centro Acidi
(currently: Laboratorio Acidi Nucleici of the IBPM, Institute of
Molecular Biology and Pathology, CNR Rome). Retired Nov.1st, 2020. Research activity: see
- Summer 1995: visiting scientist (supported by a
fellowship of the Consorzio Italiano Biotecnologie) in the
laboratory of Prof. C. Bustamante at the Institute of Molecular Biology,
Univ. Oregon, Eugene (Oregon, USA), specializing in atomic force
microscopy of nucleic acids and chromatin.
- Since 2008: expert participating in the evaluation
of EC FP6 and H2020 projects
List of publications:
- Pasqua M, Zennaro A, Trirocco R, Fanelli G, Micheli G, Grossi M,
Colonna B, Prosseda G (2021). Modulation of OMV Production by the Lysis
Module of the DLP12 Defective Prophage of Escherichia coli K12.
Microorganisms 9(2), 369
- Di Felice F, Micheli G, Camilloni G (2019). Restriction enzymes and
their use in molecular biology: An overview. J Biosci 44:38
- Leuzzi A, Grossi M, Di Martino ML, Pasqua M, Micheli G, Colonna B,
Prosseda G (2017). Role of the SRRz/Rz1 lambdoid lysis cassette in the
pathoadaptive evolution of Shigella.
Int. J. Med. Microbiol. 307:268–275
- Bolondi A, Caldarelli F, Di Felice F, Durano D, Germani G, Michetti M,
Tramutolo A, Micheli G, Camilloni G (2017). What is a Gene? A Two Sided
View. Evol. Biol. 44:1-4
- Durano D, Lukacs A, Di Felice F, Micheli G, Camilloni G (2017). A
novel role for Nhp6 proteins in histone gene regulation in Saccharomyces
cerevisiae. Int J Biochem Cell Biol. 83:76-83
- Di Martino ML, Falconi M, Micheli G, Colonna B, Prosseda G (2016). The
Multifaceted Activity of the VirF Regulatory Protein in the Shigella
Lifestyle. Front. Mol. Biosci. 3:61
- Leuzzi A, Di Martino ML , Campilongo R, Falconi M, Barbagallo M,
Marcocci L, Pietrangeli P, Casalino M, Grossi M, Micheli G, Colonna B,
Prosseda G. (2015). Multifactor Regulation of the MdtJI Polyamine
Transporter in Shigella. PLoS
- Campilongo R, Di Martino ML, Marcocci L, Pietrangeli P, Leuzzi A,
Grossi M, Casalino M, Nicoletti M, Micheli G, Colonna B, Prosseda G.
(2014). Molecular and functional profiling of the polyamine content in
enteroinvasive E. coli:
looking into the gap between commensal E.
coli and harmful Shigella.
PLos ONE 9:e106589
- Di Martino ML, Campilongo R, Casalino M, Micheli G, Colonna B,
Prosseda G. (2013). Polyamines: Emerging players in bacteria-host
interactions. Int J Med Microbiol. 303:484-491
- Prosseda G, Di Martino ML, Campilongo R, Fioravanti R, Micheli G,
Casalino M, Colonna B. (2012). Shedding of genes that interfere with the
pathogenic lifestyle: the Shigella model. Res
- Prosseda G., Mazzola A., Di Martino M.L., Tielker D., Micheli G.,
Colonna B. (2010). A temperature-induced narrow DNA curvature range
sustains the maximum activity of a bacterial promoter in vitro.
- Irene C., Maciariello C., Micheli G., Theis J.F., Newlon C.S., Fabiani
L. (2007). DNA elements modulating the KARS12
chromosomal replicator in Kluyveromyces
lactis. Mol Genet Genomics 277:287-299
- Panelli S., Damiani G., Espen L, Micheli G., Sgaramella V. (2006).
Towards the analysis of the genomes of single cells: further
characterisation of the multiple displacement amplification. Gene
- Prosseda G., Falconi M., Giangrossi M., Gualerzi C.O., Micheli G.,
Colonna B. (2004). The virF promoter in Shigella: more than just a
curved DNA stretch.2004. Mol. Microbiol. 51:523-537
- Prosseda G., Falconi M., Nicoletti M., Casalino M., Micheli G.,
Colonna B. (2002). Histone like proteins and the Shigella invasivity
regulon. Res. Microbiol. 153:461-468
- Brunetti R.,Prosseda G., Beghetto E., Colonna B., Micheli G. (2001).
The looped domain organization of the nucleoid in histone-like protein
defective Escherichia coli strains. Biochimie 83:873-82
- Falconi M., Colonna B., Prosseda G., Micheli G., Gualerzi C.O. (1998).
Thermoregulation of Shigella and Escherichia coli EIEC pathogenicity. A
temperature-dependent structural transition od DNA modulates
accessibility of virF promoter to transcriptional repressor H-NS. EMBO
- Prosseda G., Fradiani P.A., Di Lorenzo M., Falconi M., Micheli G.,
Casalino M., Nicoletti M., Colonna B. (1998). A role for H-NS in the
regulation of the virF gene of Shigella and enteroinvasive Escherichia
coli. Res. Microbiol. 149:15-25
- Ghelardini P, Liebart J.C., Di Zenzo G., Micheli G., D'Ari R.,
Paolozzi L. (1994). A novel illegitimate recombination event: precise
excision and reintegration with the Mu gem mutant prophage. Mol.
- Steinkühler C, Carrì MT, Micheli G, Knoepfel L, Weser U, Rotilio G.
(1994). Copper-dependent metabolism of Cu, Zn-superoxide dismutase in
human K562 cells. Lack of specific transcriptional activation and
accumulation of a partially inactivated enzyme. Biochemical Journal 302
- Dente L., Cesareni G., Micheli G., Felici F., Folgori A., Luzzago A.,
Monaci P., Nicosia A., Delmastro P. (1994). Monoclonal antibodies that
recognise filamentous phage: tools for phage display technology. Gene
- Carrì MT, Steinküler C, Micheli G, Rotilio G. (1994). Study on the
regulation of Cu, Zn SOD in response to stress by copper. In: Frontiers
of Reactive Oxygen Species in Biology and Medicine (Asada K, Yoshikawa
T. eds), p.291-292, Elsevier Science B.V.
- Micheli G., Ciofi Luzzatto A.R., Carrì M.T., de Capoa A., Peliccia F.
(1993). Chromosome length and DNA loop size dur ing early embryonic
development of Xenopus laevis. Chromosoma 102:478-483
- Colonna B., Bernardini M.L., Micheli G., Maimone F., Nicoletti M.,
Casalino M. (1989). Antibiotic resistance transposons on a virulence
plasmid from Salmonella wien. J. Chemother.1, 313-314.
- Colonna B., Bernardini M.L., Micheli G., Maimone F., Nicoletti M.,
Casalino M. (1988). The Salmonella wien virulence plasmid pZM3 carries
Tn1935, a multiresistance transposon containing a composite
IS1936-kanamycin resistance element. Plasmid 20:221-231.
- Amaldi F, Bertolini B, Carrì MT, Hassan G, Micheli G. (1987) In
ricordo di Mario buongiorno-nardelli 1937–1983. Italian Journal of
Zoology (formerly: Bollettino di Zoologia) 54:91-93
- Carrì M.T., Micheli G., Graziano E., Pace T., Buongiorno-Nardelli M.
(1986). The relationship between chromosomal origins of replication and
the nuclear matrix during the cell cycle. Exp. Cell Res. 164:426-436.
- Brunori M., Condò S., Bellelli A., Giardina B., Micheli G. (1985).
Tadpole Xenopus laevis hemoglobin. Correlation between stucture and
functional properties. J. Mol. Biol. 181:327-329.
- Guardiola J, Grimaldi G, Costantino P, Micheli G, Cervone F (1982).
Loss of Nitrofuran Resistance in Fusarium oxysporum is Correlated with
Loss of a 46.7 kb Circular DNA Molecule. Microbiology (formerly: Journal
of General Microbiology) 128:2235-2242
- Buongiorno-Nardelli M., Micheli G., Carrì M.T., Marilley M. (1982). A
relationship between replicon size and supercoiled loop domains in the
eukaryotic genome. Nature 298:100-102.
- Micheli G., Baldari C.T., Carrì M.T., Di Cello G., Buongiorno-Nardelli
M. (1982). An electron microscope study of chromosomal DNA replication
in different eukaryotic systems. Exp. Cell Res. 137:127-140.
- Costantino P., Mauro M.L., Micheli G., Risuleo G., Hooykaas P.J.J.,
Schilperoort R. (1981). Fingerprinting and sequence homology of plasmids
from different virulent strains of Agrobacterium rhizogenes. Plasmid
- Buongiorno-Nardelli M, MicheliG, Amaldi F, Baldari CT, Bozzoni I
(1980). Electron microscopic analysis of DNA replication in eukaryotes.
Italian Journal of Zoology (formerly: Bollettino di Zoologia) 47:253-261
- Mauro M.L., Micheli G. (1979). DNA reassociation kinetics in diploid
and phylogenetically tetraploid cyprinidae. J. Exp. Zool. 208:407-415.
- Gioacchino Micheli
Last update: February
© 2006-2021 Gioacchino Micheli