|Mutation Type||critical splice donor site|
|Coordinate||163,864,865 bp (GRCm38)|
|Base Change||C ⇒ T (forward strand)|
|Gene Name||regulating synaptic membrane exocytosis 4|
|Chromosomal Location||163,859,751-163,918,683 bp (-)|
|MGI Phenotype||PHENOTYPE: Mice homozygous for an ENU-induec allele exhibit reduced body weight. [provided by MGI curators]|
|Amino Acid Change|
|Institutional Source||Beutler Lab|
|Gene Model||predicted gene model for protein(s): [ENSMUSP00000045637 †] † probably from a misspliced transcript|
|Predicted Effect||probably null|
|Meta Mutation Damage Score||0.9493|
|Is this an essential gene?||Probably nonessential (E-score: 0.162)|
|Candidate Explorer Status||CE: excellent candidate; human score: 2.5; ML prob: 0.808|
Linkage Analysis Data
|Alleles Listed at MGI|
|Mode of Inheritance||Autosomal Recessive|
|Local Stock||Sperm, gDNA|
|Last Updated||2019-09-04 9:45 PM by Anne Murray|
|Record Created||2015-05-02 10:32 AM by Jeff SoRelle|
The diminutive phenotype was identified among G3 mice of the pedigree R2104, some of which showed reduced body weights compared to wild-type littermates (Figure 1).
|Nature of Mutation|
Whole exome HiSeq sequencing of the G1 grandsire identified 141 mutations. The body weight phenotype was linked to a mutation in Rims4: a G to A transition at base pair 163,864,865 (v38) on chromosome 2, or base pair 54,126 in the GenBank genomic region NC_000068 within the donor splice site of intron 5. Linkage was found with a recessive model of inheritance, wherein five variant homozygous mice departed phenotypically from 14 homozygous reference mice and 16 heterozygous mice (P = 1.099 x 10-7; Figure 2).
The effect of the mutation at the cDNA and protein level have not examined, but the mutation is predicted to result in the use of a cryptic splice site in exon 5. The use of a cryptic splice site would result in a transcript with a 42-base pair deletion in exon 5 and an in-frame deletion of 14 amino acids (amino acids 185-198).
The donor splice site of intron 5, which is destroyed by the diminutive mutation, is indicated in blue lettering and the mutated nucleotide is indicated in red.
Rims4 encodes RIMS4 (protein regulating synaptic membrane exocytosis 4; alternatively, RIM4γ), a member of the RIM (Rab-3 interacting molecules) family of synaptic proteins that regulate normal neurotransmitter release. There are four isoforms of the RIM proteins: RIM1 to RIM4. The RIM1 and RIM2 isoforms have longer α and β variants and a short γ variant that differ in their protein domain organization. RIM3 and RIM4 only have γ variants. RIMS4 is highly homologous to RIM2γ and RIM3γ.
RIMS4 has a C2 domain at amino acids 129-232 (Figure 3). The C2 domain putatively binds liprins, which are adaptor proteins that regulate the active zone size (1;2). The C2 domain also binds to synaptotagmin 1, which regulates neurotransmitter release (3;4). The RIM proteins bind Rab3 via their N-terminal domain, which is absent in RIMS4. Also, a central domain in RIM binds Cav2 (N and P/Q) channels to recruit the channels to the active zones.
The diminutive mutation is within intron 5, and is predicted to result in an in-frame deletion of amino acids 185-198 within the C2 domain.
For more information about Rims4, please see the record for demure.
The RIM proteins are adaptor proteins that were identified as effectors of Rab3, which is a synaptic vesicle protein that binds GTP and regulates neurotransmitter release (5;6). The RIM proteins putatively regulate neurotransmitter release by interacting with synaptic proteins (e.g., Rab3). The RIM, RIM-BP, Munc13, and liprin proteins form a single large protein complex that forms the core of the active zone. RIM proteins bind Rab3, Rab27, Munc13, and Cav2 channels. The liprins function as a link between the RIM/RIM-BP/Munc13 complex and adhesion molecules of the receptor phosphotyrosine phosphatase family. Synaptic vesicle fusion with the presynaptic membranes is dependent on the interactions between SNARE proteins on the synaptic vesicle and syntaxin-1 and SNAP-25.
The function of RIMS4 is unknown. The cause of the low body weight in the diminutive mice is unknown.
1) 94°C 2:00
The following sequence of 437 nucleotides is amplified (chromosome 2, - strand):
1 ccacaatttg aaggagcagc ctagaaccct gccttctgcc ctctgttcct agctgcctat
Primer binding sites are underlined and the sequencing primers are highlighted; the mutated nucleotide is shown in red.
1. Zhen, M., and Jin, Y. (1999) The Liprin Protein SYD-2 Regulates the Differentiation of Presynaptic Termini in C. Elegans. Nature. 401, 371-375.
2. Kaufmann, N., DeProto, J., Ranjan, R., Wan, H., and Van Vactor, D. (2002) Drosophila Liprin-Alpha and the Receptor Phosphatase Dlar Control Synapse Morphogenesis. Neuron. 34, 27-38.
3. Coppola, T., Magnin-Luthi, S., Perret-Menoud, V., Gattesco, S., Schiavo, G., and Regazzi, R. (2001) Direct Interaction of the Rab3 Effector RIM with Ca2+ Channels, SNAP-25, and Synaptotagmin. J Biol Chem. 276, 32756-32762.
4. Schoch, S., Castillo, P. E., Jo, T., Mukherjee, K., Geppert, M., Wang, Y., Schmitz, F., Malenka, R. C., and Sudhof, T. C. (2002) RIM1alpha Forms a Protein Scaffold for Regulating Neurotransmitter Release at the Active Zone. Nature. 415, 321-326.
|Science Writers||Anne Murray|
|Authors||Jeff SoRelle, Zhe Chen, and Bruce Beutler|