{PDOC00015}
{PS50079; NLS_BP}
{BEGIN}
*************************************************
* Bipartite nuclear localization signal profile *
*************************************************

The uptake  of protein by  the   nucleus  is extremely selective   and nuclear
proteins must therefore  contain within  their final  structure a signal  that
specifies selective accumulation in the nucleus [1,2]. Studies on some nuclear
proteins, such as  the  large T antigen of SV40,  have indicated which part of
the sequence  is  required  for  nuclear  translocation.   The  known  nuclear
targeting sequences  are   generally  basic, but  there  seems to  be no clear
common denominator  between  all the known sequences.  Although some consensus
sequence patterns have  been proposed (see for example [3]),  the current best
strategy to detect a nuclear targeting sequence is based [4] on  the following
definition of what is called a 'bipartite nuclear localization signal':

  (1) Two adjacent basic amino acids (Arg or Lys).
  (2) A spacer region of any 10 residues.
  (3) At least three basic residues (Arg or Lys) in the five positions
      after the spacer region.

The  profile  we  developed  covers  the entire bipartite nuclear localization
signal.

-Sequences known to belong to this class detected by the profile: 56% of known
 nuclear proteins according to [4].
-Other sequence(s) detected in Swiss-Prot: about 4.2% of  non-nuclear proteins
 according to [4].

-Note:  This profile replace an obsolete rule. All the information in the rule
 has been encoded in the profile format.

-Last update: October 2006 / Text revised; profiles added; rule deleted.

[ 1] Dingwall C., Laskey R.A.
     "Protein import into the cell nucleus."
     Annu. Rev. Cell Biol. 2:367-390(1986).
     PubMed=3548772; DOI=10.1146/annurev.cb.02.110186.002055
[ 2] Garcia-Bustos J.F., Heitman J., Hall M.N.
     Biochim. Biophys. Acta 1071:83-101(1991).
[ 3] Gomez-Marquez J., Segade F.
     FEBS Lett. 226:217-219(1988).
[ 4] Dingwall C., Laskey R.A.
     "Nuclear targeting sequences -- a consensus?"
     Trends Biochem. Sci. 16:478-481(1991).
     PubMed=1664152
{END}