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Cloning and characterization of the mouse Mcoln1 gene reveals an alternatively spliced transcript not seen in humans.

Falardeau JL, Kennedy JC, Acierno JS, Sun M, Stahl S, Goldin E, Slaugenhaupt SA - BMC Genomics (2002)

Bottom Line: The transcript that results from murine specific alternative splicing encodes a 611 amino acid protein that differs at the c-terminus.Mcoln1 is highly similar to MCOLN1, especially in the transmembrane domains and ion pore region.To date, there are very few reports describing species-specific splice variants.

View Article: PubMed Central - HTML - PubMed

Affiliation: Harvard Institute of Human Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA. falardea@helix.mgh.harvard.edu

ABSTRACT

Background: Mucolipidosis type IV (MLIV) is an autosomal recessive lysosomal storage disorder characterized by severe neurologic and ophthalmologic abnormalities. Recently the MLIV gene, MCOLN1, has been identified as a new member of the transient receptor potential (TRP) cation channel superfamily. Here we report the cloning and characterization of the mouse homologue, Mcoln1, and report a novel splice variant that is not seen in humans.

Results: The human and mouse genes display a high degree of synteny. Mcoln1 shows 91% amino acid and 86% nucleotide identity to MCOLN1. Also, Mcoln1 maps to chromosome 8 and contains an open reading frame of 580 amino acids, with a transcript length of approximately 2 kb encoded by 14 exons, similar to its human counterpart. The transcript that results from murine specific alternative splicing encodes a 611 amino acid protein that differs at the c-terminus.

Conclusions: Mcoln1 is highly similar to MCOLN1, especially in the transmembrane domains and ion pore region. Also, the late endosomal/lysosomal targeting signal is conserved, supporting the hypothesis that the protein is localized to these vesicle membranes. To date, there are very few reports describing species-specific splice variants. While identification of Mcoln1 is crucial to the development of mouse models for MLIV, the fact that there are two transcripts in mice suggests an additional or alternate function of the gene that may complicate phenotypic assessment.

No MeSH data available.


Related in: MedlinePlus

Peptide sequence comparison of the two alternatively spliced Mcoln1 isoforms. The green box surrounds the divergent c-terminal cytoplasmic tails. The blue lines indicate the transmembrane domains.
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Figure 4: Peptide sequence comparison of the two alternatively spliced Mcoln1 isoforms. The green box surrounds the divergent c-terminal cytoplasmic tails. The blue lines indicate the transmembrane domains.

Mentions: TMPred analysis predicts that isoform 2 encodes a protein identical in structure to Mcoln1, possessing 6 transmembrane domains and a channel pore, however the protein sequences diverge at amino acid 526. The 55 amino acid C-terminal cytoplasmic tail encoded by the 2.4 kb transcript is completely different from the 86 amino acid tail encoded by the murine specific 4.4 kb transcript (Fig. 4). Clontech Mouse RNA Master Blots were hybridized with the exon 2 and intron 12 probes mentioned above in an attempt to determine if these two transcripts showed differences in expression patterns, however, there was no significant difference in the 22 tissues represented (data not shown).


Cloning and characterization of the mouse Mcoln1 gene reveals an alternatively spliced transcript not seen in humans.

Falardeau JL, Kennedy JC, Acierno JS, Sun M, Stahl S, Goldin E, Slaugenhaupt SA - BMC Genomics (2002)

Peptide sequence comparison of the two alternatively spliced Mcoln1 isoforms. The green box surrounds the divergent c-terminal cytoplasmic tails. The blue lines indicate the transmembrane domains.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC88885&req=5

Figure 4: Peptide sequence comparison of the two alternatively spliced Mcoln1 isoforms. The green box surrounds the divergent c-terminal cytoplasmic tails. The blue lines indicate the transmembrane domains.
Mentions: TMPred analysis predicts that isoform 2 encodes a protein identical in structure to Mcoln1, possessing 6 transmembrane domains and a channel pore, however the protein sequences diverge at amino acid 526. The 55 amino acid C-terminal cytoplasmic tail encoded by the 2.4 kb transcript is completely different from the 86 amino acid tail encoded by the murine specific 4.4 kb transcript (Fig. 4). Clontech Mouse RNA Master Blots were hybridized with the exon 2 and intron 12 probes mentioned above in an attempt to determine if these two transcripts showed differences in expression patterns, however, there was no significant difference in the 22 tissues represented (data not shown).

Bottom Line: The transcript that results from murine specific alternative splicing encodes a 611 amino acid protein that differs at the c-terminus.Mcoln1 is highly similar to MCOLN1, especially in the transmembrane domains and ion pore region.To date, there are very few reports describing species-specific splice variants.

View Article: PubMed Central - HTML - PubMed

Affiliation: Harvard Institute of Human Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA. falardea@helix.mgh.harvard.edu

ABSTRACT

Background: Mucolipidosis type IV (MLIV) is an autosomal recessive lysosomal storage disorder characterized by severe neurologic and ophthalmologic abnormalities. Recently the MLIV gene, MCOLN1, has been identified as a new member of the transient receptor potential (TRP) cation channel superfamily. Here we report the cloning and characterization of the mouse homologue, Mcoln1, and report a novel splice variant that is not seen in humans.

Results: The human and mouse genes display a high degree of synteny. Mcoln1 shows 91% amino acid and 86% nucleotide identity to MCOLN1. Also, Mcoln1 maps to chromosome 8 and contains an open reading frame of 580 amino acids, with a transcript length of approximately 2 kb encoded by 14 exons, similar to its human counterpart. The transcript that results from murine specific alternative splicing encodes a 611 amino acid protein that differs at the c-terminus.

Conclusions: Mcoln1 is highly similar to MCOLN1, especially in the transmembrane domains and ion pore region. Also, the late endosomal/lysosomal targeting signal is conserved, supporting the hypothesis that the protein is localized to these vesicle membranes. To date, there are very few reports describing species-specific splice variants. While identification of Mcoln1 is crucial to the development of mouse models for MLIV, the fact that there are two transcripts in mice suggests an additional or alternate function of the gene that may complicate phenotypic assessment.

No MeSH data available.


Related in: MedlinePlus