Purification and characterization of CAF-I, a human cell factor required for chromatin assembly during DNA replication in vitro

Cell ◽  
1989 ◽  
Vol 58 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Susan Smith ◽  
Bruce Stillman
2007 ◽  
Vol 18 (1) ◽  
pp. 129-141 ◽  
Author(s):  
Yasunari Takami ◽  
Tatsuya Ono ◽  
Tatsuo Fukagawa ◽  
Kei-ichi Shibahara ◽  
Tatsuo Nakayama

Chromatin assembly factor-1 (CAF-1), a complex consisting of p150, p60, and p48 subunits, is highly conserved from yeast to humans and facilitates nucleosome assembly of newly replicated DNA in vitro. To investigate roles of CAF-1 in vertebrates, we generated two conditional DT40 mutants, respectively, devoid of CAF-1p150 and p60. Depletion of each of these CAF-1 subunits led to delayed S-phase progression concomitant with slow DNA synthesis, followed by accumulation in late S/G2 phase and aberrant mitosis associated with extra centrosomes, and then the final consequence was cell death. We demonstrated that CAF-1 is necessary for rapid nucleosome formation during DNA replication in vivo as well as in vitro. Loss of CAF-1 was not associated with the apparent induction of phosphorylations of S-checkpoint kinases Chk1 and Chk2. To elucidate the precise role of domain(s) in CAF-1p150, functional dissection analyses including rescue assays were preformed. Results showed that the binding abilities of CAF-1p150 with CAF-1p60 and DNA polymerase sliding clamp proliferating cell nuclear antigen (PCNA) but not with heterochromatin protein HP1-γ are required for cell viability. These observations highlighted the essential role of CAF-1–dependent nucleosome assembly in DNA replication and cell proliferation through its interaction with PCNA.


1979 ◽  
Vol 57 (6) ◽  
pp. 945-958 ◽  
Author(s):  
Kostas Iatrou ◽  
Lashitew Gedamu ◽  
Gordon H. Dixon

Poly(A)+ protamine mRNA (pmRNA) components were isolated after separation on denaturing preparative polyacrylamide gels. The four size classes of protamine mRNA described previously were found to contain poly(A) tracts of different lengths. The pmRNA1 was found to be associated with (A)110, pmRNA2 with (A)90, pmRNA3 with (A)85, and pmRNA4 with (A)69. Following deadenylation with RNase H after duplex formation with oligo-dT, the isolated mRNAs were found to be still heterogeneous, although highly enriched in certain of the deadenylated components. DNA complementary to the isolated mRNAs (cDNA) was synthesized in vitro. Following depurination, the oligopyrimidine maps indicated that C7T4, corresponding to an Arg-Arg-Gly-Gly sequence in protamine and originally thought to be characteristic of all mRNA components, is present in only one or possibly two of the components. Cross-hybridizations between the cDNAs and the four poly(A)+ pmRNAs indicated that a basic polynucleotide unit of substantial length is common to all four mRNAs and that the existing nucleotide sequence variations probably originate from one or both of the non-coding portions of the mRNA molecules.


2007 ◽  
Vol 45 (10-11) ◽  
pp. 858-865 ◽  
Author(s):  
Adeliana S. Oliveira ◽  
Ludovico Migliolo ◽  
Rodrigo O. Aquino ◽  
Jannison K.C. Ribeiro ◽  
Leonardo L.P. Macedo ◽  
...  

2013 ◽  
Vol 288 (20) ◽  
pp. 14098-14113 ◽  
Author(s):  
Nadia R. Chalfoun ◽  
Carlos F. Grellet-Bournonville ◽  
Martín G. Martínez-Zamora ◽  
Araceli Díaz-Perales ◽  
Atilio P. Castagnaro ◽  
...  

In this work, the purification and characterization of an extracellular elicitor protein, designated AsES, produced by an avirulent isolate of the strawberry pathogen Acremonium strictum, are reported. The defense eliciting activity present in culture filtrates was recovered and purified by ultrafiltration (cutoff, 30 kDa), anionic exchange (Q-Sepharose, pH 7.5), and hydrophobic interaction (phenyl-Sepharose) chromatographies. Two-dimensional SDS-PAGE of the purified active fraction revealed a single spot of 34 kDa and pI 8.8. HPLC (C2/C18) and MS/MS analysis confirmed purification to homogeneity. Foliar spray with AsES provided a total systemic protection against anthracnose disease in strawberry, accompanied by the expression of defense-related genes (i.e. PR1 and Chi2-1). Accumulation of reactive oxygen species (e.g. H2O2 and O2̇̄) and callose was also observed in Arabidopsis. By using degenerate primers designed from the partial amino acid sequences and rapid amplification reactions of cDNA ends, the complete AsES-coding cDNA of 1167 nucleotides was obtained. The deduced amino acid sequence showed significant identity with fungal serine proteinases of the subtilisin family, indicating that AsES is synthesized as a larger precursor containing a 15-residue secretory signal peptide and a 90-residue peptidase inhibitor I9 domain in addition to the 283-residue mature protein. AsES exhibited proteolytic activity in vitro, and its resistance eliciting activity was eliminated when inhibited with PMSF, suggesting that its proteolytic activity is required to induce the defense response. This is, to our knowledge, the first report of a fungal subtilisin that shows eliciting activity in plants. This finding could contribute to develop disease biocontrol strategies in plants by activating its innate immunity.


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