DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.48120#0054
36 Molecular and Cell Biology of Autoantibodies and Autoimmunity
protein overproduced in E. coli showed that La bound to ATP. A proteolytic pep-
tide of HeLa La protein representing the C-terminal 185 residues, including the
two ATP binding motifs, was shown by Chan and Tan (Mol. Cell. Biol.
7:2588-2591, 1987) to contain all of the phosphorylated residues of La protein.
Two dimensional gel analysis revealed four or five charge isomers of La protein
related to phosphorylation and/or ATP binding.
These results suggest that the La protein has two structural domains: an N-
terminal RNA binding domain and a C-terminal ATP binding domain that is
phosphorylated. Secondary structure predictions suggest that much of La is fl-
helical, including an exceptionally long putative helix stabilized by numerous salt
bridges that connects the RNA binding domain to the ATP binding domain. A
role for phosphorylation of La protein has not been determined, although possi-
ble functions include the regulation of protein-RNA interactions in La RNPs as
well as protein-protein interactions in RNA polymerase III transcription com-
plexes. We are currently investigating the amino acid sequences responsible for
conferring specificity to La protein-RNA interactions and the role of RNA bind-
ing in La-dependent transcription termination by RNA polymerase III.
Autoantibodies to “HSP 70 Class” Proteins in Sera of Systemic Lupus
Erythematosus (SLE) Patients and Healthy Subjects. A Spontaneous
Expression of HSP 70 Autoantibodies
I. Kindas-Mtigge and I. Frohlich
Institute of Tumor Biology and Cancer Research, University of Vienna, Vienna, Italy
Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease con-
taining autoantibodies to various small nuclear and cytoplasmic ribonucleopro-
tein complexes. These antibodies serve as markers of diagnostic and prognostic
significance.
It was recently found that an enhancement of heat shock protein (hsp) syn-
thesis occur in peripheral blood mononuclear cells from SLE patients [1].
Although the precise function of hsp(s) is not yet fully understood, their presum-
ed role is to protect cells from injury. Since there has been no information about
autoantibodies to heat shock proteins, we decided to look for sera containing au-
toantibodies to the mammalian “hsp 70 class” proteins, one of the most promi-
nent class of heat shock proteins.
protein overproduced in E. coli showed that La bound to ATP. A proteolytic pep-
tide of HeLa La protein representing the C-terminal 185 residues, including the
two ATP binding motifs, was shown by Chan and Tan (Mol. Cell. Biol.
7:2588-2591, 1987) to contain all of the phosphorylated residues of La protein.
Two dimensional gel analysis revealed four or five charge isomers of La protein
related to phosphorylation and/or ATP binding.
These results suggest that the La protein has two structural domains: an N-
terminal RNA binding domain and a C-terminal ATP binding domain that is
phosphorylated. Secondary structure predictions suggest that much of La is fl-
helical, including an exceptionally long putative helix stabilized by numerous salt
bridges that connects the RNA binding domain to the ATP binding domain. A
role for phosphorylation of La protein has not been determined, although possi-
ble functions include the regulation of protein-RNA interactions in La RNPs as
well as protein-protein interactions in RNA polymerase III transcription com-
plexes. We are currently investigating the amino acid sequences responsible for
conferring specificity to La protein-RNA interactions and the role of RNA bind-
ing in La-dependent transcription termination by RNA polymerase III.
Autoantibodies to “HSP 70 Class” Proteins in Sera of Systemic Lupus
Erythematosus (SLE) Patients and Healthy Subjects. A Spontaneous
Expression of HSP 70 Autoantibodies
I. Kindas-Mtigge and I. Frohlich
Institute of Tumor Biology and Cancer Research, University of Vienna, Vienna, Italy
Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease con-
taining autoantibodies to various small nuclear and cytoplasmic ribonucleopro-
tein complexes. These antibodies serve as markers of diagnostic and prognostic
significance.
It was recently found that an enhancement of heat shock protein (hsp) syn-
thesis occur in peripheral blood mononuclear cells from SLE patients [1].
Although the precise function of hsp(s) is not yet fully understood, their presum-
ed role is to protect cells from injury. Since there has been no information about
autoantibodies to heat shock proteins, we decided to look for sera containing au-
toantibodies to the mammalian “hsp 70 class” proteins, one of the most promi-
nent class of heat shock proteins.