Alternative splice variants of hTrp4 differentially interact with the C-terminal portion of the inositol 1,4,5-trisphosphate receptors

• Published in: FEBS letters Vol. 487; no. 3; pp. 377 - 383
• Main Authors: Mery, Laurence, Magnino, Fabrice, Schmidt, Karin, Krause, Karl-Heinz, Dufour, Jean-François
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 05.01.2001
• Subjects: Alternative Splicing; Amino Acid Sequence; Animals; Base Sequence; Binding Sites; Ca 2+ entry; Ca2+ entry; Calcium Channels - chemistry; Calcium Channels - classification; Calcium Channels - genetics; Calcium Channels - metabolism; DNA Primers - genetics; EYFP, enhanced yellow fluorescent protein; G3PDH, glyceraldehyde-3-phosphate dehydrogenase; GST, glutathione-S-transferase; HEK, human embryonic kidney; Humans; In Vitro Techniques; Inositol 1,4,5-triphosphate receptor; Inositol 1,4,5-Trisphosphate Receptors; InsP3, inositol 1,4,5-triphosphate; InsP3R, inositol 1,4,5-triphosphate receptor; IRES, internal ribosome entry site; Molecular Sequence Data; PCR, polymerase chain reaction; Protein Isoforms - chemistry; Protein Isoforms - genetics; Protein Isoforms - metabolism; RACE, rapid amplification of cDNA ends; Rats; Receptors, Cytoplasmic and Nuclear - chemistry; Receptors, Cytoplasmic and Nuclear - classification; Receptors, Cytoplasmic and Nuclear - genetics; Receptors, Cytoplasmic and Nuclear - metabolism; RNA, Messenger - genetics; RNA, Messenger - metabolism; SDS, sodium dodecyl sulfate; Sequence Homology, Amino Acid; SOC, store-operated channels; Tissue Distribution; Transient receptor potential protein; Trp, Transient receptor potential; TRPC Cation Channels; Trpl, Trp-like; Two-Hybrid System Techniques; Alternative splicing; Transient receptor potential protein; IRES, internal ribosome entry site; HEK, human embryonic kidney; SDS, sodium dodecyl sulfate; Ca 2+ entry; InsP 3R, inositol 1,4,5-triphosphate receptor; SOC, store-operated channels; Trp, Transient receptor potential; Inositol 1,4,5-triphosphate receptor; GST, glutathione- S-transferase; Trpl, Trp-like; EYFP, enhanced yellow fluorescent protein; PCR, polymerase chain reaction; RACE, rapid amplification of cDNA ends; InsP 3, inositol 1,4,5-triphosphate; G3PDH, glyceraldehyde-3-phosphate dehydrogenase
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/S0014-5793(00)02362-0

The molecular basis of capacitative (or store-operated) Ca 2+ entry is still subject to debate. The transient receptor potential proteins have been hypothesized to be structural components of store-operated Ca 2+ channels and recent evidence suggests that Trp3 and its closely related homolog Trp6 are gated by the N-terminal region of the inositol 1,4,5-triphosphate receptors (InsP 3R). In this study, we report the existence of two isoforms of the human Trp4 protein, referred to as α-hTrp4 and β-hTrp4. The shorter variant β-hTrp4 is generated through alternative splicing and lacks the C-terminal amino acids G 785–S 868. Using a yeast two-hybrid assay and glutathione- S-transferase-pulldown experiments, we found that the C-terminus of α-hTrp4, but not of β-hTrp4, associates in vitro with the C-terminal domain of the InsP 3 receptors type 1, 2 and 3. Thus, we describe a novel interaction between Trp proteins and InsP 3R and we provide evidence suggesting that the formation of hTrp4–InsP 3R complexes may be regulated by alternative splicing.