NameMot-2
OrganismHomo sapiens (cell culture)
Aging PhenotypeLife-span extension
Allele TypeOverexpression
StrainMRC-5 lung fibroblasts
DescriptionMot-2 is an hsp70 family member found to be differentially distributed and/or translated in normal vs. transformed cells (Wadhwa et al, 1993). Transfection of normal human fiboblasts with human or murine Mot-2 overexpression vectors led to an increase in the number of population doublings the cells could sustain before senescing (percent increase varying from 32% to 60%, depending on the exact construct used). Furthermore, the transfected cells retained a youthful morphology longer than the control cells, and there was a delay in appearance of senescence associated beta-galactosidase activity (Kaul et al, 2000).
Gene FunctionPutative heat shock protein and negative regulator of p53.
Other PhenotypesMot-2 overexpressing cells exhibited a reduction in p53 transcriptional activation, as measured by expression from vectors containing either luciferase or beta-galactosidase driven by p53 binding sites (Kaul et al, 2000). This might partially or wholly explain the effects of Mot-2 on proliferative potential, though the evidence is presently only correlative.
HomologsH.s. HSPA5, HSPA8, HSP2A
M.m. HSPA9, HSPA5, HSP70-2
D.m. HSC70-5, HSC70-3, HSC70-4
C.e. HSP-6, HSP-3, HSP-4
S.p. Ssc1, Spcc1739.13
S.c. SSC1, ECM10, SSA3
Primary ReferenceKaul, S. C., Reddelb, R. R., Sugiharac, T., Mitsuia, Y., and Wadhwa, R. (2000). Inactivation of p53 and life span extension of human diploid fibroblasts by mot-2. FEBS Lett 474, 159-64. [Abstract]
Other ReferencesWadhwa, R., Kaul, S. C., Ikawa, Y., and Sugimoto, Y. (1993). Identification of a novel member of mouse hsp70 family. Its association with cellular mortal phenotype. J Biol Chem 268, 6615-21. [Abstract]
Relevant LinksLocusLink: http://www.ncbi.nih.gov/LocusLink/LocRpt.cgi?l=3313
KeywordsSenescence, replicative lifespan, homo sapiens, heat shock, p53, cell culture