Limits...
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

Northern analysis of Mcoln1. (A) Mouse fetal tissue Northern and (B) mouse multiple tissue Northern blots (Clontech) hybridized with a probe generated from exon 2 (probe 1, Fig. 1B). (C) Hybridization of the multiple tissue blot with a probe from the alternatively spliced segment of exon 13 (probe 2, Fig. 1B). β-Actin control hybridization is shown below each blot.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC88885&req=5

Figure 3: Northern analysis of Mcoln1. (A) Mouse fetal tissue Northern and (B) mouse multiple tissue Northern blots (Clontech) hybridized with a probe generated from exon 2 (probe 1, Fig. 1B). (C) Hybridization of the multiple tissue blot with a probe from the alternatively spliced segment of exon 13 (probe 2, Fig. 1B). β-Actin control hybridization is shown below each blot.

Mentions: Mouse adult multiple tissue and embryonic Northern blots were hybridized using a probe generated from mouse exon 2 (probe 1, Fig. 1B), yielding a band of approximately 2.4 kb (isoform 1), as expected, and a less abundant and unexpected 4.4 kb band (isoform 2) (Figs. 3A &3B). The 2.4 kb band shows ubiquitous but variable expression, with the highest expression in brain, liver and kidney. The fetal tissue blot shows decreasing levels of the 2.4 kb message with increasing gestational age. Since the human MCOLN1 gene encodes a single transcript [7-9], we carried out additional hybridizations with probes generated from various regions of the coding sequence and 3' UTR, and all probes identified the same two transcripts in the mouse (data not shown). In order to verify the presence of a single mouse locus, we hybridized a mouse Southern blot with the exon 2 probe. Four different restriction enzymes were used, and only the expected size bands for the chromosome 8 locus were detected (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)

Northern analysis of Mcoln1. (A) Mouse fetal tissue Northern and (B) mouse multiple tissue Northern blots (Clontech) hybridized with a probe generated from exon 2 (probe 1, Fig. 1B). (C) Hybridization of the multiple tissue blot with a probe from the alternatively spliced segment of exon 13 (probe 2, Fig. 1B). β-Actin control hybridization is shown below each blot.
© Copyright Policy
Related In: Results  -  Collection

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

Figure 3: Northern analysis of Mcoln1. (A) Mouse fetal tissue Northern and (B) mouse multiple tissue Northern blots (Clontech) hybridized with a probe generated from exon 2 (probe 1, Fig. 1B). (C) Hybridization of the multiple tissue blot with a probe from the alternatively spliced segment of exon 13 (probe 2, Fig. 1B). β-Actin control hybridization is shown below each blot.
Mentions: Mouse adult multiple tissue and embryonic Northern blots were hybridized using a probe generated from mouse exon 2 (probe 1, Fig. 1B), yielding a band of approximately 2.4 kb (isoform 1), as expected, and a less abundant and unexpected 4.4 kb band (isoform 2) (Figs. 3A &3B). The 2.4 kb band shows ubiquitous but variable expression, with the highest expression in brain, liver and kidney. The fetal tissue blot shows decreasing levels of the 2.4 kb message with increasing gestational age. Since the human MCOLN1 gene encodes a single transcript [7-9], we carried out additional hybridizations with probes generated from various regions of the coding sequence and 3' UTR, and all probes identified the same two transcripts in the mouse (data not shown). In order to verify the presence of a single mouse locus, we hybridized a mouse Southern blot with the exon 2 probe. Four different restriction enzymes were used, and only the expected size bands for the chromosome 8 locus were detected (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