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A hypothesis for a novel role of RIN1-the modulation of telomerase function by the MAPK signaling pathway
PATRIC HAMBLETON1, MANUEL ALEJANDRO BARBIERI1,2,3,4,*
1 Department of Biological Sciences, Florida International University, Miami, 33199, USA
2 Biomedical Science Institute, Florida International University, Miami, 33199, USA
3 Fairchild Tropical Botanic Garden, Miami, 33156, USA
4 International Center of Tropical Botany, Florida International University, Miami, FL, 33199, USA
* Address correspondence to: Manuel Alejandro Barbieri,
BIOCELL 2020, 44(4), 525-534. https://doi.org/10.32604/biocell.2020.011407
Received 07 May 2020; Accepted 13 August 2020; Issue published 24 December 2020
Abstract
Cancerous cells display abnormalities in the signal transduction pathways responsible for responding to
extracellular growth factors, or mitogens. Mutations that alter proteins involved in these types of pathways can
lead to inappropriate or unregulated cell growth, and therefore predispose the cell to become malignant. The
critical role of the Ras/mitogen-activated protein kinase (MAPK) pathway in transducing growth signals to the
interior of the cell and subsequently stimulating cell growth and proliferation is underscored by the fact that
roughly one quarter of all human tumors contain mutant forms of Ras proteins. A particular focus on the
signaling and membrane trafficking adaptor protein known as Ras interference 1 (RIN1) will reveal how this
protein can potentially play a significant role in the development of the cancerous phenotype in certain cell
types. Of equal interest is the possible connection between the Ras/MAPK pathway, and subsequent expression
and enzymatic activity of telomerase–a key enzyme known to be overexpressed in roughly 85% of all cancers.
RIN1 is a 783 amino acid (84 kDa) cytosolic protein that is involved in key steps of growth factor receptormediated endocytosis and can potentially moderate signaling through the MAPK pathways. RIN1, with its
unique ability to compete directly with Raf for activation by Ras, could potentially influence signaling through
more than one of the MAPK pathways. If so, RIN1 may then be able to exert a precise and selective effect on
the downstream signal(s) of a MAPK target such as telomerase.
Keywords
Cite This Article
HAMBLETON, P., BARBIERI, M. A. (2020). A hypothesis for a novel role of RIN1-the modulation of telomerase function by the MAPK signaling pathway.
BIOCELL, 44(4), 525–534.