Atrophic macular degeneration mutations in ELOVL4 result in the intracellular misrouting of the protein

Rajesh Ambasudhan, Xiao Fei Wang, Monica Jablonski, Debra A. Thompson, Pamela S. Lagali, Paul W. Wong, Paul A. Sieving, Radha Ayyagari

Research output: Contribution to journalArticle

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Abstract

Elongation of very long chain fatty acids 4 (ELOVL4) is a novel member of the ELO family of genes that are involved in fatty acid metabolism. ELOVL4 encodes a putative transmembrane protein of 314 amino acids that carries a possible endoplasmic reticulum (ER) retention/retrieval signal (KXKXX) at the C-terminus. Two distinct mutations, a 5-bp deletion and a complex mutation from the same region in exon 6 of this gene, have been reported so far and are associated with autosomal dominant atrophic macular degeneration (adMD/STGD3). Both of these deletions could result in C-terminal truncation and loss of the ER retention signal in the mutant protein. We expressed the wild-type and mutant proteins in COS-7 and CHO cells to study the intracellular distribution of ELOVL4 and to identify possible implications of the above mutations in its localization. Immunofluorescence analysis of these proteins along with organelle marker antibodies revealed predominant ER localization for wild-type ELOVL4. Targeted deletion of the dilysine motif at the C-terminus of the protein resulted in the loss of ER localization. Immunoelectron microscopy and immunofluorescence analysis revealed a similar ER localization pattern for the protein in human photoreceptors. These data indicate that ELOVL4 is an ER-resident protein, which supports its suggested function in fatty acid elongation. We also demonstrate that the localization of both mutant proteins was dramatically changed from an ER to a Golgi distribution. Our observations suggest that the consequences of defective protein trafficking could underlie the molecular mechanism associated with degeneration of the macula in the patients with adMD/STGD3.

Original languageEnglish (US)
Pages (from-to)615-625
Number of pages11
JournalGenomics
Volume83
Issue number4
DOIs
StatePublished - Apr 1 2004
Externally publishedYes

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Macular Degeneration
Endoplasmic Reticulum
Mutation
Mutant Proteins
Proteins
Fatty Acids
Fluorescent Antibody Technique
lysyllysine
Immunoelectron Microscopy
CHO Cells
COS Cells
Protein Transport
Protein C
Organelles
Genes
Exons
Amino Acids
Antibodies

All Science Journal Classification (ASJC) codes

  • Genetics

Cite this

Ambasudhan, R., Wang, X. F., Jablonski, M., Thompson, D. A., Lagali, P. S., Wong, P. W., ... Ayyagari, R. (2004). Atrophic macular degeneration mutations in ELOVL4 result in the intracellular misrouting of the protein. Genomics, 83(4), 615-625. https://doi.org/10.1016/j.ygeno.2003.10.004

Atrophic macular degeneration mutations in ELOVL4 result in the intracellular misrouting of the protein. / Ambasudhan, Rajesh; Wang, Xiao Fei; Jablonski, Monica; Thompson, Debra A.; Lagali, Pamela S.; Wong, Paul W.; Sieving, Paul A.; Ayyagari, Radha.

In: Genomics, Vol. 83, No. 4, 01.04.2004, p. 615-625.

Research output: Contribution to journalArticle

Ambasudhan, R, Wang, XF, Jablonski, M, Thompson, DA, Lagali, PS, Wong, PW, Sieving, PA & Ayyagari, R 2004, 'Atrophic macular degeneration mutations in ELOVL4 result in the intracellular misrouting of the protein', Genomics, vol. 83, no. 4, pp. 615-625. https://doi.org/10.1016/j.ygeno.2003.10.004
Ambasudhan, Rajesh ; Wang, Xiao Fei ; Jablonski, Monica ; Thompson, Debra A. ; Lagali, Pamela S. ; Wong, Paul W. ; Sieving, Paul A. ; Ayyagari, Radha. / Atrophic macular degeneration mutations in ELOVL4 result in the intracellular misrouting of the protein. In: Genomics. 2004 ; Vol. 83, No. 4. pp. 615-625.
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