TY - JOUR
T1 - Immunoelectron microscopic analysis of the intracellular distribution of primer recognition proteins, annexin 2 and phosphoglycerate kinase, in normal and transformed cells
AU - Kumble, K. D.
AU - Vishwanatha, Jamboor K.
PY - 1991/9/17
Y1 - 1991/9/17
N2 - Primer recognition proteins (PRP) are accessory proteins for DNA polymerase α in lagging strand DNA replication. We have previously reported that the PRP consist of a complex of two proteins identified as 3-phosphoglycerate kinase (PGK) and the protein-tyrosine kinase substrate, annexin 2 monomer. The physiological role of annexin 2 is not known. Two pools of annexin 2 exist in cells. A majority of annexin 2 is localized with the plasma membrane as a heterotetramer in association with a light chain. Monomer annexin 2 is cytosolic. The identification of annexin 2 monomer as a part of the PRP complex represents one of the physiological roles of this protein in cells. To function as PRP, annexin 2 and PGK would have to be present in the cell nucleus. To investigate whether monomer annexin 2 is indeed associated with nuclear DNA synthesis, we investigated the presence of annexin 2 and PGK in the cell nucleus. In this paper, we demonstrate the presence of annexin 2 and PGK in nuclear extracts. The nuclear fraction of these proteins represents a small subset of the total cellular pools. Immunoelectron-microscopic analyses using anti-PRP antisera demonstrate the distribution of these proteins in HeLa cell nuclei and cytoplasm. Under identical conditions, an anticytokeratin monoclonal antibody preferentially labels the plasma membrane without detectable intracellular staining. The distribution of annexin 2 and PGK in both nuclei and cytoplasm is similarly observed in cells from normal tissues such as freshly isolated rat hepatocytes and hamster pancreatic tissue. The results presented in this report further substantiate the involvement of annexin 2 and PGK, as part of the PRP complex, in nuclear DNA synthesis.
AB - Primer recognition proteins (PRP) are accessory proteins for DNA polymerase α in lagging strand DNA replication. We have previously reported that the PRP consist of a complex of two proteins identified as 3-phosphoglycerate kinase (PGK) and the protein-tyrosine kinase substrate, annexin 2 monomer. The physiological role of annexin 2 is not known. Two pools of annexin 2 exist in cells. A majority of annexin 2 is localized with the plasma membrane as a heterotetramer in association with a light chain. Monomer annexin 2 is cytosolic. The identification of annexin 2 monomer as a part of the PRP complex represents one of the physiological roles of this protein in cells. To function as PRP, annexin 2 and PGK would have to be present in the cell nucleus. To investigate whether monomer annexin 2 is indeed associated with nuclear DNA synthesis, we investigated the presence of annexin 2 and PGK in the cell nucleus. In this paper, we demonstrate the presence of annexin 2 and PGK in nuclear extracts. The nuclear fraction of these proteins represents a small subset of the total cellular pools. Immunoelectron-microscopic analyses using anti-PRP antisera demonstrate the distribution of these proteins in HeLa cell nuclei and cytoplasm. Under identical conditions, an anticytokeratin monoclonal antibody preferentially labels the plasma membrane without detectable intracellular staining. The distribution of annexin 2 and PGK in both nuclei and cytoplasm is similarly observed in cells from normal tissues such as freshly isolated rat hepatocytes and hamster pancreatic tissue. The results presented in this report further substantiate the involvement of annexin 2 and PGK, as part of the PRP complex, in nuclear DNA synthesis.
KW - Annexin 2
KW - Immunogold DNA replication
KW - Phosphoglycerate kinase
KW - Primer recognition proteins
UR - http://www.scopus.com/inward/record.url?scp=0025917329&partnerID=8YFLogxK
M3 - Article
C2 - 1837552
AN - SCOPUS:0025917329
SN - 0021-9533
VL - 99
SP - 751
EP - 758
JO - Journal of Cell Science
JF - Journal of Cell Science
IS - 4
ER -