scholarly journals The major low-molecular-weight heat shock protein in chloroplasts shows antigenic conservation among diverse higher plant species.

1989 ◽  
Vol 9 (2) ◽  
pp. 461-468 ◽  
Author(s):  
E Vierling ◽  
L M Harris ◽  
Q Chen
Keyword(s):  
Molecular Weight ◽  
Heat Shock ◽  
Plant Species ◽  
Fusion Proteins ◽  
Higher Plants ◽  
Low Molecular Weight ◽  
Amino Terminal ◽  
Terminal Domain ◽  
Wide Range ◽  
Carboxyl Terminal

Several plant species are known to synthesize low-molecular-weight nucleus-encoded heat shock proteins (HSPs) which localize to chloroplasts. DNA sequence analysis of chloroplast HSP cDNAs from pea (Pisum sativum) and soybean (Glycine max) has shown that the carboxyl-terminal halves of these proteins are homologous to low-molecular-weight HSPs from a wide range of eucaryotes (E. Vierling, R. T. Nagao, A. E. DeRocher, and L. M. Harris, EMBO J. 7:575-581, 1988). We used a pea cDNA to construct fusion proteins containing either the carboxyl-terminal heat shock domain or the amino-terminal domain of the chloroplast HSP. The fusion proteins were overexpressed in Escherichia coli and used to produce choloroplast HSP-specific polyclonal antibodies. The carboxyl-terminal antibodies recognized chloroplast HSP precursor proteins from pea and from three divergent plant species, Arabidopsis thaliana, petunia (Petunia hybrida), and maize (Zea mays). The amino-terminal antibodies recognized effectively only the pea precursor. When intact plants of each species were subjected to a heat stress regime mimicking field growth conditions, significant levels of the mature forms of the chloroplast HSPs accumulated in pea, A. thaliana, and maize. The levels of accumulated HSPs remained unchanged for 12 h following the stress treatment. We conclude that the synthesis of chloroplast-localized HSPs is an important component of the stree response in all higher plants and that chloroplast HSPs from dicotyledonous and monocotyledonous plants have a conserved carboxyl-terminal domain.

The major low-molecular-weight heat shock protein in chloroplasts shows antigenic conservation among diverse higher plant species

1989 ◽  
Vol 9 (2) ◽  
pp. 461-468
Author(s):  
E Vierling ◽  
L M Harris ◽  
Q Chen
Keyword(s):  
Molecular Weight ◽  
Heat Shock ◽  
Plant Species ◽  
Fusion Proteins ◽  
Higher Plants ◽  
Low Molecular Weight ◽  
Amino Terminal ◽  
Terminal Domain ◽  
Wide Range ◽  
Carboxyl Terminal

Several plant species are known to synthesize low-molecular-weight nucleus-encoded heat shock proteins (HSPs) which localize to chloroplasts. DNA sequence analysis of chloroplast HSP cDNAs from pea (Pisum sativum) and soybean (Glycine max) has shown that the carboxyl-terminal halves of these proteins are homologous to low-molecular-weight HSPs from a wide range of eucaryotes (E. Vierling, R. T. Nagao, A. E. DeRocher, and L. M. Harris, EMBO J. 7:575-581, 1988). We used a pea cDNA to construct fusion proteins containing either the carboxyl-terminal heat shock domain or the amino-terminal domain of the chloroplast HSP. The fusion proteins were overexpressed in Escherichia coli and used to produce choloroplast HSP-specific polyclonal antibodies. The carboxyl-terminal antibodies recognized chloroplast HSP precursor proteins from pea and from three divergent plant species, Arabidopsis thaliana, petunia (Petunia hybrida), and maize (Zea mays). The amino-terminal antibodies recognized effectively only the pea precursor. When intact plants of each species were subjected to a heat stress regime mimicking field growth conditions, significant levels of the mature forms of the chloroplast HSPs accumulated in pea, A. thaliana, and maize. The levels of accumulated HSPs remained unchanged for 12 h following the stress treatment. We conclude that the synthesis of chloroplast-localized HSPs is an important component of the stree response in all higher plants and that chloroplast HSPs from dicotyledonous and monocotyledonous plants have a conserved carboxyl-terminal domain.

FKLF-2: a novel Krüppel-like transcriptional factor that activates globin and other erythroid lineage genes

Blood ◽  
2000 ◽  
Vol 95 (11) ◽  
pp. 3578-3584 ◽  
Author(s):  
Haruhiko Asano ◽  
Xi Susan Li ◽  
George Stamatoyannopoulos
Keyword(s):  
Cell Lines ◽  
Dna Sequences ◽  
Zinc Finger Protein ◽  
Globin Gene ◽  
Northern Blot Hybridization ◽  
Gene Promoters ◽  
Amino Terminal ◽  
Terminal Domain ◽  
Wide Range ◽  
Carboxyl Terminal

Abstract FKLF-2, a novel Krüppel-type zinc finger protein, was cloned from murine yolk sac. The deduced polypeptide sequence of 289 amino acids has 3 contiguous zinc fingers at the near carboxyl-terminal end, an amino-terminal domain characterized by its high content of alanine and proline residues and a carboxyl-terminal domain rich in serine residues. By Northern blot hybridization, the human homologue of FKLF-2 is expressed in the bone marrow and striated muscles and not in 12 other human tissues analyzed. FKLF-2 is constitutively expressed in established cell lines with an erythroid phenotype, but it is inconsistently expressed in cell lines with myeloid or lymphoid phenotypes. The expression of FKLF-2 messenger RNA (mRNA) is up-regulated after induction of mouse erythroleukemia cells. In luciferase assays, FKLF-2 activates predominantly the γ, and to a lesser degree, the ɛ and β globin gene promoters. The activation of γ gene promoter does not depend on the presence of an HS2 enhancer. FKLF-2 activates the γ promoter predominantly by interacting with the γ CACCC box, and to a lesser degree through interaction with the TATA box or its surrounding DNA sequences. FKLF-2 also activated all the other erythroid specific promoters we tested (GATA-1, glycophorin B, ferrochelatase, porphobilinogen deaminase, and 5-aminolevulinate synthase). These results suggest that in addition to globin, FKLF-2 may be involved in activation of transcription of a wide range of genes in the cells of the erythroid lineage.

FKLF-2: a novel Krüppel-like transcriptional factor that activates globin and other erythroid lineage genes

Blood ◽  
2000 ◽  
Vol 95 (11) ◽  
pp. 3578-3584 ◽  
Author(s):  
Haruhiko Asano ◽  
Xi Susan Li ◽  
George Stamatoyannopoulos
Keyword(s):  
Cell Lines ◽  
Dna Sequences ◽  
Zinc Finger Protein ◽  
Globin Gene ◽  
Northern Blot Hybridization ◽  
Gene Promoters ◽  
Amino Terminal ◽  
Terminal Domain ◽  
Wide Range ◽  
Carboxyl Terminal

FKLF-2, a novel Krüppel-type zinc finger protein, was cloned from murine yolk sac. The deduced polypeptide sequence of 289 amino acids has 3 contiguous zinc fingers at the near carboxyl-terminal end, an amino-terminal domain characterized by its high content of alanine and proline residues and a carboxyl-terminal domain rich in serine residues. By Northern blot hybridization, the human homologue of FKLF-2 is expressed in the bone marrow and striated muscles and not in 12 other human tissues analyzed. FKLF-2 is constitutively expressed in established cell lines with an erythroid phenotype, but it is inconsistently expressed in cell lines with myeloid or lymphoid phenotypes. The expression of FKLF-2 messenger RNA (mRNA) is up-regulated after induction of mouse erythroleukemia cells. In luciferase assays, FKLF-2 activates predominantly the γ, and to a lesser degree, the ɛ and β globin gene promoters. The activation of γ gene promoter does not depend on the presence of an HS2 enhancer. FKLF-2 activates the γ promoter predominantly by interacting with the γ CACCC box, and to a lesser degree through interaction with the TATA box or its surrounding DNA sequences. FKLF-2 also activated all the other erythroid specific promoters we tested (GATA-1, glycophorin B, ferrochelatase, porphobilinogen deaminase, and 5-aminolevulinate synthase). These results suggest that in addition to globin, FKLF-2 may be involved in activation of transcription of a wide range of genes in the cells of the erythroid lineage.

NOM and MIB, who wins in the competition for activated carbon adsorption sites?

2004 ◽  
Vol 49 (9) ◽  
pp. 257-265 ◽  
Author(s):  
C. Hepplewhite ◽  
G. Newcombe ◽  
D.R.U. Knappe
Keyword(s):  
Molecular Weight ◽  
Activated Carbons ◽  
Background Concentration ◽  
Low Molecular Weight ◽  
Activated Carbon Adsorption ◽  
Microporous Carbons ◽  
Adsorption Sites ◽  
Carbon Adsorption ◽  
Competitive Mechanism ◽  
Wide Range

The adsorption of an odour compound common in drinking water, 2-methylisoborneol (MIB), was studied on two activated carbons in the presence of 13 well-characterised natural organic matter (NOM) solutions. It was found that, although the carbons and the NOM solutions had a wide range of characteristics, the major competitive mechanism was the same in all cases. The low molecular weight NOM compounds were the most competitive, participating in a direct competition with the MIB molecule for adsorption sites. Equivalent background concentration (EBC) calculations indicated a relatively low concentration of directly competing compounds in the NOM. Some evidence of pore restriction was also seen, with microporous carbons most affected by low molecular weight NOM, and mesoporous carbons impacted by the higher molecular weight compounds.

scholarly journals Presequence and mature part of preproteins strongly influence the dependence of mitochondrial protein import on heat shock protein 70 in the matrix.

1993 ◽  
Vol 123 (1) ◽  
pp. 119-126 ◽  
Author(s):  
W Voos ◽  
B D Gambill ◽  
B Guiard ◽  
N Pfanner ◽  
E A Craig
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Fusion Protein ◽  
Fusion Proteins ◽  
Dual Role ◽  
Intermembrane Space ◽  
Heme Binding ◽  
Membrane Translocation ◽  
Amino Terminal ◽  
The Matrix

To test the hypothesis that 70-kD mitochondrial heat shock protein (mt-hsp70) has a dual role in membrane translocation of preproteins we screened preproteins in an attempt to find examples which required either only the unfoldase or only the translocase function of mt-hsp70. We found that a series of fusion proteins containing amino-terminal portions of the intermembrane space protein cytochrome b2 (cyt. b2) fused to dihydrofolate reductase (DHFR) were differentially imported into mitochondria containing mutant hsp70s. A fusion protein between the amino-terminal 167 residues of the precursor of cyt. b2 and DHFR was efficiently transported into mitochondria independently of both hsp70 functions. When the length of the cyt. b2 portion was increased and included the heme binding domain, the fusion protein became dependent on the unfoldase function of mt-hsp70, presumably caused by a conformational restriction of the heme-bound preprotein. In the absence of heme the noncovalent heme binding domain in the longer fusion proteins no longer conferred a dependence on the unfoldase function. When the cyt. b2 portion of the fusion protein was less than 167 residues, its import was still independent of mt-hsp70 function; however, deletion of the intermembrane space sorting signal resulted in preproteins that ended up in the matrix of wild-type mitochondria and whose translocation was strictly dependent on the translocase function of mt-hsp70. These findings provide strong evidence for a dual role of mt-hsp70 in membrane translocation and indicate that preproteins with an intermembrane space sorting signal can be correctly imported even in mutants with severely impaired hsp70 function.

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