Sequences of several nucleolar localization signals in which one or more clusters of basic amino acids are present.

These clusters of basic amino acids can be found in human proteins as MDM2 [16], p14ARF [17], SVV-EX3 [15], NIK [18], hLa [19], ING-I [20], NOLP [21], IGF-I [22], Werner [23], Nucleolin [24], Parafibromin [25], PTHrP [26], DEDD [27], Angiogenin [28] and in several viral proteins such as Protein alpha [29], MEQ (protein of Marek’s disease virus (MDV) [30], Tat [31] and Rev [32] (both proteins of human immunodeficiency virus type 1), Rex (protein of human T lymphotropic virus type [33], I14L (protein of African swine fever virus) [34]. Basic amino acids are shown in bold letters. Motifs of two or more K/R are underlined.