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Regulation of the phosphorylation of human pharyngeal cell proteins by group A streptococcal surface dehydrogenase: signal transduction between streptococci and pharyngeal cells.

Pancholi V, Fischetti VA - J. Exp. Med. (1997)

Bottom Line: Intact streptococci and purified SDH induce a similar protein phosphorylation pattern with the de novo tyrosine phosphorylation of a 17-kD protein found in the membrane/particulate fraction of the pharyngeal cells.Treatment of pharyngeal cells with protein kinase inhibitors such as genistein and staurosporine significantly inhibited streptococcal invasion of pharyngeal cells.To identify the membrane receptor that elicits these signaling events, we found that SDH bound specifically to 30- and 32-kD membrane proteins in a direct ligand-binding assay.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Bacterial Pathogenesis and Immunology, The Rockefeller University, New York 10021, USA. panchov@rockvax.rockefeller.edu

ABSTRACT
Whether cell-to-cell communication results when group A streptococci interact with their target cells is unknown. Here, we report that upon contact with cultured human pharyngeal cells, both whole streptococci and purified streptococcal surface dehydrogenase (SDH) activate pharyngeal cell protein tyrosine kinase as well as protein kinase C, thus regulating the phosphorylation of cellular proteins. SDH, a major surface protein of group A streptococci, has both glyceraldehyde-3-phosphate dehydrogenase and ADP-ribosylating enzyme activities that may relate to early stages of streptococcal infection. Intact streptococci and purified SDH induce a similar protein phosphorylation pattern with the de novo tyrosine phosphorylation of a 17-kD protein found in the membrane/particulate fraction of the pharyngeal cells. However, this phosphorylation required the presence of cytosolic components. NH2-terminal amino acid sequence analysis identified the 17-kD protein as nuclear core histone H3. Both phosphotyrosine and phosphoserine-specific monoclonal antibodies reacted with the 17-kD protein by Western blot, suggesting that the binding of SDH to these pharyngeal cells elicits a novel signaling pathway that ultimately leads to activation of histone H3-specific kinases. Genistein-inhibitable phosphorylation of histone H3 indicates that tyrosine kinase plays a key role in this event. Treatment of pharyngeal cells with protein kinase inhibitors such as genistein and staurosporine significantly inhibited streptococcal invasion of pharyngeal cells. Therefore, these data indicated that streptococci/SDH-mediated phosphorylation plays a critical role in bacterial entry into the host cell. To identify the membrane receptor that elicits these signaling events, we found that SDH bound specifically to 30- and 32-kD membrane proteins in a direct ligand-binding assay. These findings clearly suggest that SDH plays an important role in cellular communication between streptococci and pharyngeal cells that may be important in host cell gene transcription, and hence in the pathogenesis of streptococcal infection.

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32P-labeled proteins  of the FaDu pharyngeal cell M/P  fraction. Autoradiographs showing 32P-labeled proteins of the  M/P fraction after phosphorylation of intact pharyngeal cells.  FaDu cells were prepared, processed, and treated with group A  streptococci and purified SDH as  described in Fig. 1.
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Figure 2: 32P-labeled proteins of the FaDu pharyngeal cell M/P fraction. Autoradiographs showing 32P-labeled proteins of the M/P fraction after phosphorylation of intact pharyngeal cells. FaDu cells were prepared, processed, and treated with group A streptococci and purified SDH as described in Fig. 1.

Mentions: To determine the ability of streptococci/ SDH to regulate phosphorylation of cellular proteins of other human pharyngeal cell lines, we used another established pharyngeal cell line, FaDu, and compared the protein phosphorylation profile with that of Detroit cells. The results (Fig. 2) show a similar phosphorylation pattern in control untreated FaDu cells. FaDu cells treated with intact streptococci show a marked increase in protein phosphorylation in the M/P fraction with a de novo phosphorylation of the 17-kD protein as observed in Detroit cells (Fig. 1). However, unlike the Detroit cells (Fig. 1), the de novo incorporation of labeled 32P in the 17-kD protein of FaDu cells in the presence of purified SDH increased only slightly. These data confirm the role of intact streptococci in regulating phosphorylation of pharyngeal cell proteins, and indicate that the interaction of streptococci with FaDu cells may be similar to that found with Detroit cells. The interaction of purified SDH with FaDu cells leading to relatively less incorporation of labeled 32P in the 17-kD protein suggests that this interaction may be cell-type dependent, and, accordingly, may result in different signaling pathways.


Regulation of the phosphorylation of human pharyngeal cell proteins by group A streptococcal surface dehydrogenase: signal transduction between streptococci and pharyngeal cells.

Pancholi V, Fischetti VA - J. Exp. Med. (1997)

32P-labeled proteins  of the FaDu pharyngeal cell M/P  fraction. Autoradiographs showing 32P-labeled proteins of the  M/P fraction after phosphorylation of intact pharyngeal cells.  FaDu cells were prepared, processed, and treated with group A  streptococci and purified SDH as  described in Fig. 1.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2199133&req=5

Figure 2: 32P-labeled proteins of the FaDu pharyngeal cell M/P fraction. Autoradiographs showing 32P-labeled proteins of the M/P fraction after phosphorylation of intact pharyngeal cells. FaDu cells were prepared, processed, and treated with group A streptococci and purified SDH as described in Fig. 1.
Mentions: To determine the ability of streptococci/ SDH to regulate phosphorylation of cellular proteins of other human pharyngeal cell lines, we used another established pharyngeal cell line, FaDu, and compared the protein phosphorylation profile with that of Detroit cells. The results (Fig. 2) show a similar phosphorylation pattern in control untreated FaDu cells. FaDu cells treated with intact streptococci show a marked increase in protein phosphorylation in the M/P fraction with a de novo phosphorylation of the 17-kD protein as observed in Detroit cells (Fig. 1). However, unlike the Detroit cells (Fig. 1), the de novo incorporation of labeled 32P in the 17-kD protein of FaDu cells in the presence of purified SDH increased only slightly. These data confirm the role of intact streptococci in regulating phosphorylation of pharyngeal cell proteins, and indicate that the interaction of streptococci with FaDu cells may be similar to that found with Detroit cells. The interaction of purified SDH with FaDu cells leading to relatively less incorporation of labeled 32P in the 17-kD protein suggests that this interaction may be cell-type dependent, and, accordingly, may result in different signaling pathways.

Bottom Line: Intact streptococci and purified SDH induce a similar protein phosphorylation pattern with the de novo tyrosine phosphorylation of a 17-kD protein found in the membrane/particulate fraction of the pharyngeal cells.Treatment of pharyngeal cells with protein kinase inhibitors such as genistein and staurosporine significantly inhibited streptococcal invasion of pharyngeal cells.To identify the membrane receptor that elicits these signaling events, we found that SDH bound specifically to 30- and 32-kD membrane proteins in a direct ligand-binding assay.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Bacterial Pathogenesis and Immunology, The Rockefeller University, New York 10021, USA. panchov@rockvax.rockefeller.edu

ABSTRACT
Whether cell-to-cell communication results when group A streptococci interact with their target cells is unknown. Here, we report that upon contact with cultured human pharyngeal cells, both whole streptococci and purified streptococcal surface dehydrogenase (SDH) activate pharyngeal cell protein tyrosine kinase as well as protein kinase C, thus regulating the phosphorylation of cellular proteins. SDH, a major surface protein of group A streptococci, has both glyceraldehyde-3-phosphate dehydrogenase and ADP-ribosylating enzyme activities that may relate to early stages of streptococcal infection. Intact streptococci and purified SDH induce a similar protein phosphorylation pattern with the de novo tyrosine phosphorylation of a 17-kD protein found in the membrane/particulate fraction of the pharyngeal cells. However, this phosphorylation required the presence of cytosolic components. NH2-terminal amino acid sequence analysis identified the 17-kD protein as nuclear core histone H3. Both phosphotyrosine and phosphoserine-specific monoclonal antibodies reacted with the 17-kD protein by Western blot, suggesting that the binding of SDH to these pharyngeal cells elicits a novel signaling pathway that ultimately leads to activation of histone H3-specific kinases. Genistein-inhibitable phosphorylation of histone H3 indicates that tyrosine kinase plays a key role in this event. Treatment of pharyngeal cells with protein kinase inhibitors such as genistein and staurosporine significantly inhibited streptococcal invasion of pharyngeal cells. Therefore, these data indicated that streptococci/SDH-mediated phosphorylation plays a critical role in bacterial entry into the host cell. To identify the membrane receptor that elicits these signaling events, we found that SDH bound specifically to 30- and 32-kD membrane proteins in a direct ligand-binding assay. These findings clearly suggest that SDH plays an important role in cellular communication between streptococci and pharyngeal cells that may be important in host cell gene transcription, and hence in the pathogenesis of streptococcal infection.

Show MeSH
Related in: MedlinePlus