Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.59 (MIP)
 4,906 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Water channels are the subject of much current attention, as they may be central for cell functions in a host of tissues. We have analyzed the possible field of facilitators and water channels of the MIP family based on structural predictions, on findings about the topology of CHIP28, and on the biophysical characteristics of water channels. We developed predictions for the following proteins: MIP26, NOD26, GLP, BIB, gamma-TIP, FA-CHIP, CHIP28k, WCH-CD1, and CHIP28. We utilized Kyte Doolittle hydrophobicity, Eisenberg's amphiphilicity, Chou-Fasman-Prevelige propensities, and our own Union algorithm. We found that hydrophobic amphiphilic segments likely to be transmembrane were consistently shorter than required for alpha-helical segments, but of the correct length for beta-strands. Turn propensity was high at frequent intervals, consistent with transmembrane beta-strands. We propose that these proteins fold as porin-like 16-stranded antiparallel beta-barrels. In water channels, from the size of molecules excluded, an extramembrane loop(s) would enter the pore and restrict it to a bottleneck with a width 4 A < or = w < or = 5 A. A similar but more mobile loop(s) would act as gate and binding site for the facilitators of the MIP family.
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PMID:Predictive evidence for a porin-type beta-barrel fold in CHIP28 and other members of the MIP family. A restricted-pore model common to water channels and facilitators. 753 97

Water is essential for all living organisms. Aquaporin proteins are the major facilitator of water transport activity through cell membranes of plants including soybean. These proteins are diverse in plants and belong to a large major intrinsic (MIP) protein family. In higher plants, MIPs are classified into five subfamilies including plasma membrane intrinsic proteins (PIP), tonoplast intrinsic proteins (TIP), NOD26-like intrinsic proteins (NIP), small basic intrinsic proteins (SIP), and the recently discovered X intrinsic proteins (XIP). This paper reports genome wide assembly of soybean MIPs, their functional prediction and expression analysis. Using a bioinformatic homology search, 66 GmMIPs were identified in the soybean genome. Phylogenetic analysis of amino acid sequences of GmMIPs divided the large and highly similar multi-gene family into 5 subfamilies: GmPIPs, GmTIPs, GmNIPs, GmSIPs and GmXIPs. GmPIPs consisted of 22 genes and GmTIPs 23, which showed high sequence similarity within subfamilies. GmNIPs contained 13 and GmSIPs 6 members which were diverse. In addition, we also identified a two member GmXIP, a distinct 5(th) subfamily. GmMIPs were further classified into twelve subgroups based on substrate selectivity filter analysis. Expression analyses were performed for a selected set of GmMIPs using semi-quantitative reverse transcription (semi-RT-qPCR) and qPCR. Our results suggested that many GmMIPs have high sequence similarity but diverse roles as evidenced by analysis of sequences and their expression. It can be speculated that GmMIPs contains true aquaporins, glyceroporins, aquaglyceroporins and mixed transport facilitators.
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PMID:Genome-wide sequence characterization and expression analysis of major intrinsic proteins in soybean (Glycine max L.). 2343 13