Progerin

Progerin (UniProt# P02545-6) is a truncated version of the lamin A protein involved in the pathology of Hutchinson–Gilford progeria syndrome. Progerin is most often generated by a sporadic single point nucleotide polymorphism c.1824 C>T (GGC -> GGT, p.Gly608Gly) in the gene that codes for matured Lamin A.[1] This mutation activates a cryptic splice site that induces a larger mutation in the processed prelamin A messenger RNA, causing the deletion of a 50 amino-acid group near the C-terminus of the prelamin A protein.[2] The endopeptidase ZMPSTE24 cannot cleave between the missing RSY - LLG amino acid sequence (as seen in the figure) during the maturation of Lamin A, due to the deletion of the 50 amino acids which included that sequence. This leaves the intact premature Lamin A bonded to the methylated carboxyl farnesyl group creating the defective protein Progerin, rather than the desired protein matured Lamin A. Approximately 90% of all Hutchinson–Gilford progeria syndrome cases are heterozygous for this deleterious single nucleotide polymorphism within exon 11 of the LMNA gene causing the post-translational modifications to produce progerin.[3]

Normal (left) prelamin A processing and the defective gene Progerin (right) without the 50 AA sequence processing.

Lamin A constitutes a major structural component of the lamina, a scaffold of proteins found inside the nuclear membrane of a cell; progerin does not properly integrate into the lamina, which disrupts the scaffold structure and leads to significant disfigurement of the nucleus, characterized by a globular shape.[4] Progerin activates genes that regulate stem cell differentiation via the Notch signaling pathway.[5] Progerin increases the frequency of unrepaired double-strand breaks in DNA following exposure to ionizing radiation.[6] Also, overexpression of progerin is correlated with an increase in non-homologous end joining relative to homologous recombination among those DNA double-strand breaks that are repaired.[7] Furthermore, the fraction of homologous recombination events occurring by gene conversion is increased. These findings suggest that the normal untruncated nuclear lamina has an important role in the proper repair of DNA double-strand breaks.[6]

  1. ^ McClintock, Dayle; Gordon, Leslie B.; Djabali, Karima (2006-02-14). "Hutchinson–Gilford progeria mutant lamin A primarily targets human vascular cells as detected by an anti-Lamin A G608G antibody". Proceedings of the National Academy of Sciences. 103 (7): 2154–2159. Bibcode:2006PNAS..103.2154M. doi:10.1073/pnas.0511133103. ISSN 0027-8424. PMC 1413759. PMID 16461887.
  2. ^ Eriksson, Maria; Brown, W. Ted; Gordon, Leslie B.; Glynn, Michael W.; Singer, Joel; Scott, Laura; Erdos, Michael R.; Robbins, Christiane M.; Moses, Tracy Y.; Berglund, Peter; Dutra, Amalia (May 2003). "Recurrent de novo point mutations in lamin A cause Hutchinson–Gilford progeria syndrome". Nature. 423 (6937): 293–298. Bibcode:2003Natur.423..293E. doi:10.1038/nature01629. hdl:2027.42/62684. ISSN 0028-0836. PMC 10540076. PMID 12714972. S2CID 4420150.
  3. ^ Gordon, Leslie B.; Brown, W. Ted; Collins, Francis S. (1993), Adam, Margaret P.; Ardinger, Holly H.; Pagon, Roberta A.; Wallace, Stephanie E. (eds.), "Hutchinson-Gilford Progeria Syndrome", GeneReviews®, Seattle (WA): University of Washington, Seattle, PMID 20301300, retrieved 2022-04-26
  4. ^ "Anti-cancer Drugs May Hold Promise For Premature Aging Disorder". ScienceDaily. Retrieved 2022-04-26.
  5. ^ Scaffidi, Paola; Misteli, Tom (April 2008). "Lamin A-dependent misregulation of adult stem cells associated with accelerated ageing". Nature Cell Biology. 10 (4): 452–459. doi:10.1038/ncb1708. ISSN 1476-4679. PMC 2396576. PMID 18311132.
  6. ^ a b Noda, Asao; Mishima, Shuji; Hirai, Yuko; Hamasaki, Kanya; Landes, Reid D.; Mitani, Hiroshi; Haga, Kei; Kiyono, Tohru; Nakamura, Nori; Kodama, Yoshiaki (December 2015). "Progerin, the protein responsible for the Hutchinson-Gilford progeria syndrome, increases the unrepaired DNA damages following exposure to ionizing radiation". Genes and Environment. 37 (1): 13. doi:10.1186/s41021-015-0018-4. ISSN 1880-7062. PMC 4917958. PMID 27350809.
  7. ^ Komari, Celina J.; Guttman, Anne O.; Carr, Shelby R.; Trachtenberg, Taylor L.; Orloff, Elise A.; Haas, Ashley V.; Patrick, Andrew R.; Chowdhary, Sona; Waldman, Barbara C.; Waldman, Alan S. (December 2020). "Alteration of genetic recombination and double-strand break repair in human cells by progerin expression". DNA Repair. 96: 102975. doi:10.1016/j.dnarep.2020.102975. PMC 7669652. PMID 33010688.