Os09g02650

The rice Brittle Culm 12 (BC12) gene encodes a dual-targeting kinesin-4 protein, controls cell-cycle progression and wall properties in rice.

Function

This gene encodes a kinesin-4 protein, which is participated in cell-cycle progression, cellulose microfibril deposition and cell wall composition in the monocot plant rice. bc12 mutants display dwarfism resulting from a significant reduction in cell number and brittleness due to an alteration in cellulose microfibril orientation and wall composition. Similar to the typical kinesin-4 in animals,BC12 has an nuclear locational signal (NLS) and functions in mitosis. BC12 is present in both the nucleus and cytoplasm and associated with microtubule arrays during cell division. BC12 interacts with CDKA;3 (cyclin-dependent kinase) and probably undergoing phosphorylation for the purpose of regulation. BC12 is essential to exert multiple roles in cell division and cell wall biogenesis in rice.

Mutation

bc12: A 26bp deletion in the 4th exon of one open reading frame (ORF), results in a frameshift. which is related with the dwarfism and brittleness phenotype.

Expression pattern

BC12 is universally expressed in all organs. with higher expression in panicles and culms. RNA in situ hybridization reveals that BC12 is expressed in young tissues, includeing the initiating adventitious roots, primary root tips, flower primordia and intercalary meristems, all tissues in which cells are undergoing vigorous cell division.

Structure

The CDS coordinates(5'-3') of this gene is from 1158082 to 1167873. The ORF of the BC12 is 3108 nucleotides long and encodes a kinesin protein of the kinesin-4 subfamily which is 1036 amino acid residues long. The predicted molecular weight is about 116386, and the predicted pI is 9.4858. BC12 harbors a conserved motor domain at the N-terminus, a neck linker after the motor domain,a long coiled-coil region and the NLS at the C-terminus. The coiled-coil region is responsible for dimerization. BC12 shows microtubule-dependent ATPase activity, and the neck linker plays a critical role for this activity.

Sequence

The sequence of this gene are as following:

  1 ATGACGATGG AGCACGGCGA GGATTGCTGC GTCAAGGTGG CCGTCCATGT  CCGCCCGCTC ATCGGCGACG AGAAGCTTCA GGGCTGTAAG GACTGCGTCT
101 CCGTCGTCTC CGGCAAGCCG CAGGTTCAGA TCGGGAGCCA TTCCTTCACC  TTCGACCATG TGTACGGCAG CTCCGGCACG CCGTCGGCGG CCATGTTCGA
201 GGAGTGCGTG GCGCCGCTCG TCGACGGCCT CTTCCAGGGC TACAACGCCA  CCGTGCTCGC ATACGGCCAG ACTGGGTCAG GGAAGACCTA CACCATGGGG
301 ACGGCCTGCA AGGAGGGCTC ACACATTGGG ATTATCCCGC GTGCCATGGC  CACGCTGTTC GACAAGATCG ACAAGCTCAA GAACCAAGTA GAGTTCCAGC
401 TGCGCGTTTC GTTTATTGAG ATTCTGAAAG AAGAGGTGAG GGATTTGCTT  GATCCTGCTA CTGCTGCTGT TGGCAAACTT GAGAATGGAA ATGGACATGC
501 AACCAAGTTG TCGGTTCCAG GTAAACCCCC TGTTCAGATC CGGGAGGCGT  CGAACGGGGT CATAACGTTA GCAGGATCGA CCGAAGTGCA TGTCACTACC
601 CAGAAAGAAA TGACGGCATG CCTTGAGCAA GGATCTCTGA GTCGTGCAAC  TGGAAGTACC AACATGAACA ACCAATCAAG TCGTTCCCAT GCCATCTTCA
701 CAATCACATT GGAGCAGATG CGCAAAGCAG ATCCCATCAT GACTTTAGAT  GGAATGCCTA TTGAAGAGAT GAATGAAGAC TATCTCTGTG CCAAACTCCA
801 CTTAGTAGAT CTTGCTGGAT CAGAACGTGC TAAAAGAACT GGTTCTGATG  GCCTTCGGTT TAAGGAAGGT GTTCATATCA ACAGAGGACT TCTTGCTCTT
901 GGCAATGTCA TCAGTGCTCT CGGTGATGAG AAAAAGAGGA AAGAAGGCGC  TCATGTTCCT TACCGGGACA GCAAACTCAC TCGCCTTCTG CAGGACTCTC

1001 TAGGTGGAAA CAGCAAGACT GTAATGATAG CCTGTATTAG TCCAGCAGAT ATCAATGCTG AAGAAACACT GAACACTTTG AAATATGCTA ACCGCGCTCG 1101 TAACATCCAG AATAAGCCAA TTGTAAATAG AAATCCTGTT GCTGATGAGA TGAAAAGGAT GCGCCAGCAA ATTGAATACT TGCAAGCAGA ACTCGTTTCA 1201 GCTCGAGGAG GAGTTGTCTT AGATGATGTT CAGGGTCTCA GGGAAAGGAT CTCAATGCTT GAACAGAAAA ATGAAGACCT TTGCAGGGAA CTGTATGACC 1301 TTCGCAACCA TGGTTACACT GATCCTTGTG AACCTGAACT GCAAAAAATT GGAACTGGTT ACACTAAAGG TGAAGGGCTC AAAAGAAGCT TGCAAAGTAC 1401 AGAACCATTT GATGTCCCCA TGACTGACTC AGTAAGAGCA GGCAGCCCTA AAGATATTGA TGATGAAGTG GCCAAAGAAT GGGAACACAC AATGCTGCAG 1501 GATAGCATGG GCAAAGAGTT GAATGAATTA AACAGACAAC TGGAGCAAAA GGAGTCTGAG ATGAAAATGT ATGGATCTGA CACTGTTGCA CTTAAACAAC 1601 ACTTTGGAAA GAAACTTTTG GAGCTTGAAG AAGAGAAAAG AGCTGTACAG CAAGAAAGGG ACAGATTGTT AGCTGAAGTT GAAAGTCTAA ATGCTGATGG 1701 ACAAACACAC AAGTTGCGAG ATGCCCAGCT GCAAAAATTA AAAACCCTTG AAGCACAGAT TCTAGACCTC AAGAAAAAGC AGGAGAACCA AGTTCAACTT 1801 CTGAAGGAAA AGCAAAAGAG TGATGAAGCT GCTAAGAAGT TGCAGGAAGA AATTCATTCT ATAAAGGCAC AGAAGGTTCA ACTACAACAT AAAATCAAAC 1901 AAGAAGCGGA ACAATTCCGG CAATGGAAGG CTACCCGTGA AAAGGAACTC CTGCAGTTGA GGAAAGAGGG GCGGCGAAAT GAGTATGAAC GCCACAAACT 2001 TCAAGCACTT AATCAGCGGC AGAAGTTGGT TTTGCAGAGG AAGACTGAAG AAGCTGCGAT GGCTACCAAA AGGCTGAAAG AGTTACTAGA GGCTCGGAAA 2101 TCATCAGGAC GTGACAACTC AGGCATGAAT GGTACTTCTC CTGGCTCTCA TATGACTGAG AAATCATTGC AAAAATGGCT AGAGCAAGAT TTGGAAGTCA 2201 TGGTGCATGT TCATGAAGTT CGAAACGAAT ATGAAAAGCA AAGTCAATTG CGTGCTGCAC TTGGTGAGGA GCTTGCCATT TTAAAACAAG AAGATGTCAT 2301 GTCTGGTGCA GCTAGTCCGC CCAGAGGGAA GAATGGAAAC TCTAGGGCAA ATACTTTGTC ACCAAATGCA AGACAAGCTA GGATAGCATC ACTTGAAAGC 2401 ATGGTGACAA TATCTTCAAA TACTCTCGTT GCTATGGCTT CTCAACTCTC AGAAGCTGAA GAAAGAGAGC GTGCATTCTC TGGGCGTGGT CGGTGGAATC 2501 AGTTGCGTTC AATGGCAGAG GCAAAGAGTT TACTGCAGTA TATATTTAAC GTTGCTGCAG ATGCAAGATG CCAAGTAAGG GAGAAAGAGA TGGAGATCAA 2601 GGAAATGAAG GAGCAAATGA CAGAGCTTGT GACCATCCTT CGACACAGCG AATCACGTAG AAGGGAAACG GAAAAGCAGC TTAAGCAAAG AGAGCAGGCA 2701 GCTGTAACTG CCACTACATC TCCAGGAAAC GGAAATGGTT CAGTGAAGCA CTCTGCTGAT GACTCCAACA CACCATTGTC ACCAGTTGCG GTGCCTGCAC 2801 AGAAGCAGCT GAAGTACTCT GCTGGAATTG TAAATAGCCC CAGCAAAGGG GTTCCTGCAT TCAACAAACA ACATCTTAAG ATGGTTCCTA TGGCACAGTT 2901 GCCTGTTGGC AAGAAGGTTT CAATAGCAGG GCAATCAGGA AAACTTTGGA GATGGAAAAG AAGCCACCAC CAGTGGCTAC TGCAGTTCAA GTGGAAGTGG 3001 CAAAAGCCCT GGAAATTGTC CGAGATGATT CGACACAGTG ACGAAACGAT GACAAGGACT CGACCCAGAC CCCAGCTTCT TCCTCATAGA CCTCAAAGAG 3101 TGATGTGA

Knowledge extension

FRA1(FRAGILE FIBER 1) is the homolog gene of BC12 in Arabidopsis. FRA1 which is found in the cytoplasm,was the first functionally identified kinesin-4 member in plants. The fra1 mutant exhibits reduced plant height and fragile fibers as a result of aberrant deposition of cellulose microfibrils in the cell wall.