Exp Mol Med.  2008 Aug;40(4):377-386. 10.3858/emm.2008.40.4.377.

Transient phosphorylation of tumor associated microtubule associated protein (TMAP)/cytoskeleton associated protein 2 (CKAP2) at Thr-596 during early phases of mitosis

• Hong KU
• Choi YB
• Lee JH
• Kim HJ
• Kwon HR
• Seong YS
• Kim HT
• Park J
• Bae CD
• Hong KM

• KMID: 1094117
• DOI: http://doi.org/10.3858/emm.2008.40.4.377

Abstract

Tumor associated microtubule associated protein (TMAP), also known as cytoskeleton associated protein 2 (CKAP2) is a mitotic spindle-associated protein whose expression is cell cycle-regulated and also frequently deregulated in cancer cells. Two monoclonal antibodies (mAbs) against TMAP/CKAP2 were produced: B-1-13 and D-12-3. Interestingly, the reactivity of mAb D-12-3 to TMAP/CKAP2 was markedly decreased specifically in mitotic cell lysate. The epitope mapping study showed that mAb D-12-3 recognizes the amino acid sequence between 569 and 625 and that phosphorylation at T596 completely abolishes the reactivity of the antibody, suggesting that the differential reactivity originates from the phosphorylation status at T596. Immunofluorescence staining showed that mAb D-12-3 fails to detect TMAP/CKAP2 in mitotic cells between prophase and metaphase, but the staining becomes evident again in anaphase, suggesting that phosphorylation at T596 occurs transiently during early phases of mitosis. These results suggest that the cellular functions of TMAP/CKAP2 might be regulated by timely phosphorylation and dephosphorylation during the course of mitosis.

Keyword

antibodies, monoclonal; cell cycle; CKAP2 protein, human; fluorescent antibody technique, direct; phosphorylation

MeSH Terms

Amino Acid Sequence
Animals
Antibodies, Monoclonal/metabolism/pharmacology
Cell Cycle/physiology
Cells, Cultured
Cytoskeletal Proteins/chemistry/immunology/*metabolism/physiology
Epitope Mapping
Hela Cells
Humans
Mice
Mitosis/*physiology
Molecular Sequence Data
Phosphorylation
Protein-Serine-Threonine Kinases/*metabolism
Sequence Homology, Amino Acid
Threonine/metabolism