Homeotic proteins participate in the function of human-DNA replication origins.
Recent evidence points to homeotic proteins as actors in the crosstalk between development and DNA replication. The present work demonstrates that HOXC13, previously identified as a new member of human DNA replicative complexes, is a stable component of early replicating chromatin in living cells: it displays a slow nuclear dynamics due to its anchoring to the DNA minor groove via the arginine-5 residue of the homeodomain. HOXC13 binds in vivo to the lamin B2 origin in a cell-cycle-dependent manner consistent with origin function; the interaction maps with nucleotide precision within the replicative complex. HOXC13 displays in vitro affinity for other replicative complex proteins; it interacts also in vivo with the same proteins in a cell-cycle-dependent fashion. Chromatin-structure modifying treatments, disturbing origin function, reduce also HOXC13-origin interaction. The described interactions are not restricted to a single origin nor to a single homeotic protein (also HOXC10 binds the lamin B2 origin in vivo). Thus, HOX complexes probably contribute in a general, structure-dependent manner, to origin identification and assembly of replicative complexes thereon, in presence of specific chromatin configurations.
Marchetti
Laura
L
NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Laboratorio di Biologia Molecolare, Scuola Normale Superiore, Pisa, Italy. l.marchetti@sns.it
Comelli
Laura
L
D'Innocenzo
Barbara
B
Puzzi
Luca
L
Luin
Stefano
S
Arosio
Daniele
D
Calvello
Mariantonietta
M
Mendoza-Maldonado
Ramiro
R
Peverali
Fiorenzo
F
Trovato
Fabio
F
Riva
Silvano
S
Biamonti
Giuseppe
G
Abdurashidova
Gulnara
G
Beltram
Fabio
F
Falaschi
Arturo
A
D000818:Animals; D002460:Cell Line; D002843:Chromatin / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000032:analysis / Q000378:metabolism; D006367:HeLa Cells; D018398:Homeodomain Proteins / Q000032:analysis / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D034921:Lamin Type B / Q000032:analysis; D051379:Mice; D041681:NIH 3T3 Cells; D018741:Replication Origin
D002843:Chromatin; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D034921:Lamin Type B