Title |
Reversible function of RapA with the C-terminus of RapC in Dictyostelium |
Author |
Dongju Kim, Wonbum Kim, and Taeck Joong Jeon* |
Address |
Department of Integrative Biological Sciences & BK21 FOUR Educational Research Group for Age-associated Disorder Control Technology, Chosun University, Gwangju 61452, Republic of Korea |
Bibliography |
Journal of Microbiology, 59(9),853-848, 2021,
|
DOI |
10.1007/s12275-021-1400-5
|
Key Words |
Ras proteins, RapA, RapC, Dictyostelium, Rap1 |
Abstract |
Rap small GTPases are involved in diverse signaling pathways
associated with cell growth, proliferation, and cell migration.
There are three Rap proteins in Dictyostelium, RapA, RapB,
and RapC. RapA is a key regulator in the control of cell adhesion
and migration. Recently RapA and RapC have been
reported to have opposite functions in the regulation of cellular
processes. In this study, we demonstrate that the C-terminus
of RapC, which is not found in RapA, is essential for
the opposite functions of RapC and is able to reverse the functions
of RapA when fused to the tail of RapA. Cells lacking
RapC displayed several defective phenotypes, including spread
morphology, strong adhesion, and decreased cell migration
compared to wild-type cells. These phenotypes were rescued
by full-length RapC, but not by RapC missing the C-terminus.
Furthermore, recombinant RapA fused with the C-terminus
of RapC completely recovered the phenotypes of rapC
null cells, indicating that the functions of RapA were modified
to become similar to those of RapC by the C-terminus of
RapC with respect to cell morphology, cell adhesion and migration,
cytokinesis, and development. These results suggest
that the C-terminal residues of RapC are able to suppress and
change the functions of other Ras proteins in Ras oncogenic
signaling pathways. |