Table 1 Human canonical and non-canonical core histones of the H2A family with their chromosomal location, expression and function

Canonical H2A core histones

1

HIST1H2AA

H2A type 1-A

6p22.2 (in histone cluster 1)

Replication-dependent

Core component of nucleosome

[18]

2

HIST1H2AB

H2A type 1-B/E

6p22.2 (in histone cluster 1)

Replication-dependent

Core component of nucleosome

[18]

3

HIST1H2AE

6p22.2 (in histone cluster 1)

4

HIST1H2AC

H2A type 1-C

6p22.2 (in histone cluster 1)

Replication-dependent

Core component of nucleosome

[18]

5

HIST1H2AD

H2A type 1-D

6p22.2 (in histone cluster 1)

Replication-dependent

Core component of nucleosome

[18]

6

HIST1H2AH

H2A type 1-H

6p22.1 (in histone cluster 1)

Replication-dependent

Core component of nucleosome

[18]

7

HIST1H2AJ

H2A type 1-J

6p22.1 (in histone cluster 1)

Replication-dependent

Core component of nucleosome

[18]

8

HIST1H2AG

H2A type 1

6p22.1 (in histone cluster 1)

Replication-dependent

Core component of nucleosome

[18]

9

HIST1H2AI

6p22.1 (in histone cluster 1)

10

HIST1H2AK

6p22.1 (in histone cluster 1)

11

HIST1H2AL

6p22.1 (in histone cluster 1)

12

HIST1H2AM

6p22.1 (in histone cluster 1)

13

HIST2H2AA

H2A type 2-A

1q21.2 (in histone cluster 2)

Replication-dependent

Core component of nucleosome

[18]

14

HIST2H2AB

H2A type 2-B

1q21.2 (in histone cluster 2)

Replication-dependent

Core component of nucleosome

[18]

15

HIST2H2AC

H2A type 2-C

1q21.2 (in histone cluster 2)

Replication-dependent

Core component of nucleosome

[18]

16

HIST3H2A

H2A type 3

1q42.13 (in histone cluster 3)

Replication-dependent

Core component of nucleosome

[18]

Non-canonical H2A core histones

1

H2AX

H2A.X

11q23.3

Replication-independent

Required for cell cycle arrest and DNA repair after DNA damage

[19,20,21,22]

2

H2AZ1

H2A.Z

4q23

Replication-independent

Involvement in the formation of constitutive heterochromatin and in gene expression regulation

[23, 24]

3

H2AZ2

H2A.Z.2.1

7p13

Replication-independent (enriched in brain)

Involvement in the binding of regulatory complexes

[25]

H2A.Z.2.2

Destabilization of nucleosome

[26]

4

H2AB1, H2AB2 and H2AB3

H2A.Bbd type1, H2A.Bbd type2 and H2A.Bbd type3

Xq28

Replication-independent

Required for mRNA processing and association with active transcription and replication

[27, 28]

5

MACROH2A1

macroH2A1.1

5q31.1

Replication-independent

Involvement in ADP-ribose-mediated chromatin modulation and increase in the expression of genes involved in redox metabolism (such as SOD3)

[29, 30]

macroH2A1.2

Replication-independent

Repression of SOD3 gene expression

[30]

6

MACROH2A2

macroH2A2

10q22.1

Replication-independent

Involvement in stable X chromosome inactivation

[31]